Systematic Accounts of Species and Subspecies (part 1)

Mustela Erminea Linnaeus

Ermine

(Synonymy under subspecies)

Type.—Mustela erminea Linnaeus, Systema Naturae, 10th ed., p. 46, 1758.

Range.—From the British Isles and Atlantic Coast of Europe across Eurasia and North America including Greenland, from the northernmost land, south, in North America, to the lower margin of the Canadian Life-zone; geographically south to Connecticut, New York, Pennsylvania, northeastern Ohio, southern Michigan, Wisconsin, northern Iowa, Minnesota, North Dakota, in the Rocky Mountains to northern New Mexico, in the Sierra Nevada to Mono County, California, and on the Pacific Coast to the Golden Gate.

Characters for ready recognition.—Differs from Mustela rixosa in presence of black pencil on tail, tail-vertebrae more than a fourth of length of head and body, and in regions where the two species occur together, basilar length of skull more than 32.5 in males and more than 31.0 in females; from Mustela frenata, in regions where the two species occur together, by tail less than 44 per cent of length of head and body and by postglenoidal length of skull more than 46 per cent of condylobasal length in males and more than 48 per cent in females.

Characters of the species.—Size medium to small (total length 225 to 340 mm. in males and 190 to 290 mm. in females); tail 30 to 45 per cent of length of head and body, with distinct black pencil; caudal vertebrae 16 to 19; skull with long braincase and short precranial portion; postglenoidal length, when expressed as a percentage of the condylobasal length, more than 48 in females and ordinarily more than 46 in males; upper parts brown; underparts whitish, ordinarily continuous from chin to inguinal region but in subspecies in the humid region along the Pacific Coast interrupted in some individuals by brown of upper parts encircling body in the abdominal region. The soles of the feet in each of the subspecies are densely haired in winter and have only a relatively small area of the foot-pads exposed in summer, the intervening areas being well haired even at that season. The uniformity throughout the species as regards hairiness of the foot-soles and also the character of the vibrissae makes it unnecessary to describe these features in the accounts of the subspecies of erminea.

Geographic variation.—In the Old World 16 or more subspecies are currently recognized and there are 20 in North America. The features in which geographic variation is especially prominent are: First, size, as expressed by external measurements and weight, second, color pattern, depending on the extent, in relation to one another, of the dark-colored upper parts and light-colored underparts, and third, breadth and depth of the rostral region of the skull. Except in size, the variation in the skull is less than in M. frenata. Likewise in tone and shade of upper parts and hue or tint of underparts, erminea is less variable than frenata and has the face all of one color without the contrasting color-pattern of the face and head seen in many subspecies of frenata. M. erminea exceeds frenata as regards variation of the size of the area occupied by the light-colored underparts. At one extreme is the subspecies arctica in which the area of the light color extends well up on the sides of the body, down the insides of the legs, over the feet and far out on the lower side of the tail whereas at the other extreme are the races streatori and olympica in which the light-colored underparts are restricted to two areas, one on the chin, throat and chest, and the other on the inguinal region. These areas may or may not be connected by a thin line of white color along the midline of the underparts. In size of animal, erminea probably exhibits the maximum variation among American species of weasels; an average-sized male of the race arctica weighs 4 times as much as one of the race muricus, and in the species frenata I doubt that the difference is quite as great between individuals of the smallest race, effera, on the one hand, and either of the largest races, texensis or macrophonius, on the other hand although actual weights are not available for these races of frenata. As elsewhere indicated, the small-sized individuals of M. erminea are of the southern races and the large-sized individuals are of the northern races. This decrease in size southward occurs both in Asia and in America.

Natural History.—Habitat and numbers.—Along the International Boundary east of the Turtle Mountains, Soper (1946:136) found this species present only in timbered areas and absent from many untimbered areas. Of the same species to the westward he comments "so far as I know at present, there is no evidence to show that any short-tailed weasels inhabit a broad strip of treeless territory immediately north of the International Boundary in Canada from southwestern Alberta to southeastern Saskatchewan." The same author (1942) reports that in the general area of Wood Buffalo Park, Northwest Territory, south of Great Slave Lake, the ermine is uncommon on pine-grown sand ridge and rolling upland and common in lower spruce-aspen parklands, stream-side coniferous belts, and grassy, semi-wooded swamplands.

Nine ermines per square mile is the number that Soper (1919:46-47) estimated at Edmonton on the basis of the numbers that he trapped there in the winters of 1912-13 and 1913-14 and on the basis of the tracks of remaining ermines. From corresponding data he estimated the population in the winter of 1913 on the Hay River, north of Jasper Park, to be nine per square mile. In each of these instances he estimated ten weasels per square mile but he inclined to the view that one-tenth of the animals involved in his counts were long-tailed weasels (Mustela frenata). Osgood (1909B:30) and his field companion in the period July 31 to September 3, 1903, took a series of 42 specimens within a radius of 500 yards of their camp at the head of Seward Creek, Alaska, all caught in four traps, in one month. Of the 42 specimens, 28 are males and 14 are females.

Fluctuations of a multiannual nature are marked in this species. Bailey (1929:156) observes that in Sherburne County, Minnesota, when meadow mice are abundant for two or three years these weasels become abundant but that when the mice are scarce the weasels also become scarce. Manning (1943:56), on Southampton Island, noted "that the maximum and minimum points of the weasel cycle are much more sharply marked than those of the fox cycle and the increase and decrease are more rapid."

How far an ermine will travel in a given length of time has seldom been recorded but Hamilton (1933:293), on March 20, 1932, "followed the track of a small weasel, presumably a male cicognanii, for four miles in the fresh snow," and Ingles (1942) observed a diminutive ermine of the subspecies M. e. muricus, at Woods Lake, California, 286 yards from its den.

Behavior

As regards locomotion, Soper (1919:46), in reference to Mustela cicognanii, presumably in Ontario, Canada, writes that in the bounding gait the hind feet register almost, if not exactly, in the front-foot impressions, with the right front and hind feet lagging slightly behind. "The distance normally is about 19 inches, representing a regular rate of travel. . . . In traversing open spaces they resort to long, graceful leaps upwards of six feet in length. . . . I measured a record . . . of 8 feet, 2 inches."

Of M. e. arctica, Dice (1921:22) writes that when it runs "the tail is carried off the ground usually at an angle of about 45 degrees." Seton (1929 (2):598) states that "At Carberry [Manitoba] I have often seen this energetic little creature seeking for Mice in the deep, soft snow. Its actions are much like those of an Otter pursuing salmon. Sometimes it gallops along a log, or over an icy part of the drift; then plunges out of sight in a soft place, to reappear many yards away. . . ."

Little is recorded concerning swimming but on this score Seton (1929 (2):602) does quote J. W. Curran, who in July, 1899, at Lake Couchiching, Ontario, watched an ermine pursue a chipmunk into the water and for 100 yards before giving up the chase and wheeling around and making for shore. In swimming "The Weasel, I think, showed more of his body, and seemed to exert himself more" than the chipmunk.

As to voice, Dice (1921:22), at Tanana, Alaska, heard the ermine, when excited, bark somewhat like a mink but not so loud and Seton (1929 (2):606) quotes Manley Hardy to the effect that the species has a purring note.

Sense of smell was used by an M. e. muricus that Dixon (1931:72) watched as the ermine followed a three-fourths-grown pika. Concerning the ermine at Carberry, Manitoba, Seton (1929 (2):598-599) writes that "The smell of blood must be as far-reaching as it is attractive to these sanguinary little creatures. I have frequently hung new-killed Rabbits and partridges temporarily in trees, and, after an absence, in some cases of a few minutes only, have found an Ermine mauling the game, though there was no sign of such a visitor when the cache was made."

Enemies

George Measham, of Winnipeg, found sign in the snow indicating that a great snowy owl had killed an ermine and T. McIlwraith shot a bald eagle at Hamilton Bay which had the bleached skull of a weasel (probably of this species) clinging to the throat (Seton, 1929 (2):603).

A. B. Howell (1943:98) likens mustelid mammals to domestic cats in their manner of crossing roads and thinks that mustelids loiter at the side of the road until the stimulus of the approaching car causes them to make a dash whereupon they are caught by the wheels and killed. Three of four weasels seen to cross the road were killed, one even having apparently crossed the road before turning back and being killed under the car. One weasel killed was Mustela erminea cicognanii. Dalquest (1948:190) in writing of this species in the state of Washington, says "I have seen only one abroad in the daytime. It dashed from a roadside thicket . . . and was crushed beneath the wheels of a car."

Food

The killing of prey is described by Hamilton (1933:332) as follows: "A rapid dash, and the bird or mouse is grabbed over the back of the skull, the fore legs encircle the animal as though hugging it, and the hind legs are brought up to scratch wildly at the captive. . . . If [the prey is] a large animal, as a rat, the weasel usually lies on its side, while the diminishing struggles of the rodent continue, but if a mouse or a small bird [is the object of attack], the weasel is apt to crouch over its prey. Little time is lost over the first [mouse] . . . if two mice are present [;] a strong bite through the brain case . . . [is] sufficient. If only one animal is present, the weasel dawdles over its kill some time after life has departed."

Hamilton's (1933:333) study of the contents of the digestive tracts of bodies of ermines obtained from fur trappers and fur buyers in New York enabled him to publish the following "Frequency Indices of Mammal Genera in Fall and Winter Food of 191 Mustela cicognanii": Microtus, 35.7 per cent; mammals undetermined to genus but principally mice, 16.3; Blarina, 15.1; Peromyscus, 11.4; Sylvilagus, 9.0; Sorex, 4.9; Rattus, 4.4; Tamias, 3.6. Close correspondence is shown by the following data of Aldous and Manweiler (1942) for the ermine from Lake of the Woods, Minnesota: mice, 58.7 per cent by number and 54.5 by volume; shrews 22.5 and 21.8 per cent; birds, 2.7 and 5.0 per cent. Of the mice in stomachs, 40 per cent were microtines, 15 per cent were Peromyscus and 45 per cent were unidentified as to kind. Fragments of a small fish were found in one stomach. Summed up, the dominant winter foods were mice and shrews. Trapping of the mammal populations was done to see what the available food was and it was found that the small mammals were eaten in direct ratio to their relative abundance. Snowshoe rabbits and red squirrels were not eaten. The Minnesotan data were from 60 stomachs and 53 intestinal tracts recovered from 129 weasels trapped by use of scent (not bait) mostly from January 1 to February 7, 1939, although a few were trapped in 1938. Analyses of contents from stomachs gave approximately the same results as those from intestines. In 1939 at Lake of the Woods, weasels were concentrated where food was abundant but no such concentration was noted in the following winter.

Big short-tailed shrew (Blarina brevicauda).—In New York State, the ermine preys on Blarina as shown by Hamilton's (1933:330) seeing one being carried by a male ermine on May 6, 1931, and another being carried by a female on May 13, 1932. The same author (1928:249) found the remains of a Blarina in a small female from Malone, New York. Kirk (1921) observed, however, that the ermine (M. e. cicognanii) avoided the shrew, Blarina, caught in a trap and that Blarina avoided the weasel caught in a trap.

Chipmunk (genus Tamias).—Remains were found in a male ermine in New York on May 14, 1932 (Hamilton, 1933:330), and Seton (1929 (2):602) records a chipmunk at Lake Couchiching, Ontario, that was pursued into the water by an ermine.

Deer mice (genus Peromyscus).—As shown by Hamilton (1933:33) and Aldous and Manweiler (1942), Peromyscus was second only to microtines in numerical abundance among the food items of ermines in New York and Minnesota. Peromyscus and microtine rodents were brought to a den of the diminutive M. e. muricus in early August, in Fresno County, California, according to Ingles (1942). He observed that an Alpine chipmunk was active under and around the tree and that juncos reared young 40 feet from the den but that the chipmunk and juncos were unmolested by the ermines.

Lemming (genus Lemmus).—One was recovered from a female ermine (with milk in her glands) at Laurier Pass, British Columbia (Sheldon, 1932:201).

Red-backed mouse (genus Clethrionomys).—Criddle and Criddle (1925:146) record that on "May 31, 1921.—Saw a Bonaparte's weasel capture a Red-backed Vole after a long hunt during which the pursuer never once lost track of its victim."

Meadow mice (genus Microtus).—As shown by the data of Hamilton (1933:333) and Aldous and Manweiler (1942) recorded above, Microtus is the item of first importance in the diet of the ermine in New York and Minnesota. Criddle and Criddle (1925:146) write concerning the vicinity of Treesbank, Manitoba, that "October, 1918.—Following a severe outbreak of mice in 1916-17, Bonaparte's weasel increased enormously and very soon reduced the rodents to comparative rarity. This resulted in a scarcity of food for the weasels, which in their turn became greatly reduced in numbers."

Old World rat (Rattus).—Bishop (1923) found two headless rats near a nest of this species in Albany, New York.

Pika (Ochotona).—Dixon (1931:72) at Milner Pass, Colorado, on July 20, 1931, saw an ermine, of the subspecies muricus, following a three-fourths grown pika by scent and outrunning the pika. The pikas worked a relay system and the weasel abandoned the trail when the fourth pika became the object of the chase.

Cottontail (genus Sylvilagus).—Hamilton (1933:33), as noted above, found remains of cottontail in the digestive tracts of ermine that had been trapped for fur in winter. Possibly these remains were bait that had been placed at traps.

Snowshoe rabbit (Lepus americanus).—Morse (1939:210) in a study of predation on hares and grouse in the period of notable decimation of these two game species in 1935-1936 in the Cloquet Valley State Forest, in St. Louis County, Minnesota, found that "weasel predation on hares appeared to be of very low incidence or altogether lacking."

Wild birds (Class Aves).—Aldous and Manweiler (1942), as noted above, found that the remains of birds constituted five per cent by volume of the food of the ermine in winter in Minnesota.

Chicken (genus Gallus).—Criddle and Criddle (1925:145), who published relatively extensive data on the three species of weasels of Manitoba, write that: "We have no record of Bonaparte's weasel killing poultry, and we doubt whether it ever does so." However, Soper (1919:46) investigated the excited cackling of a hen brooding chicks at night and found a solitary ermine that had killed three chicks and that had the remainder under very active scrutiny.

Leopard frog (Rana pipiens).—One frog was found in a male ermine on November 20, 1931, in New York by Hamilton (1933:300).

Fish (Class Pisces).—Aldous and Manweiler (1942) found fragments of a small fish in one of 60 stomachs of ermine from Minnesota.

Earthworm (Phylum Annelida).—Osgood (1936:64), presumably at Rutland, Vermont, observed a pair of weasels from 2:15 P.M. to 5:00 P.M., in a barn and saw the female in that time make many trips for food for her young. Only earthworms were brought. Fifty traps in an adjacent, swampy field caught only one bull frog and no mice indicating that mice had been eliminated from the foraging territory of the ermine.

In handling food, Dice (1921:22) noted that the Alaskan ermine did not use the feet but only the mouth.

Reproduction

Litters of 4, 4, 7, 7, and 8, yielding an average of 6 young per litter have been recorded from the northeastern United States by Hamilton (1933:327). He (op. cit.:321-325) described animals one day old from New York State as being flesh-colored, having the long neck of the adult and a fine growth of white hair two milli meters in length, on the dorsal surface of the neck, that foreshadows the mane or pompadour that is prominent from the 14th to the 21st day of life. Six animals, when one day old averaged 1.7 grams in weight, which was three per cent of the weight of an adult female and one and one half per cent of the weight of an adult male. At two weeks of age the heavy brown mane stood out in marked contrast to the rest of the scantily, white-furred animal. The eyes opened on the thirty-fifth day of life.

For rearing their young, ermines live in burrows. Bishop (1923), in Albany, New York, found a burrow occupied by four young and a pair of adults. The burrow had many galleries and contained a nest constructed of rat fur, fine grass and fragments of leaves. At Woods Lake, Fresno County, California, in early August, Ingles observed (1942) some young and at least one adult at their den which was in a burrow beneath a hollow tree. The ermines used the hollow root and the hollow tree as well as the burrow beneath. Seton (1929 (2):591) quotes S. Eldon Percival, of Barretts Rapids, Ontario, as finding the living quarters of an ermine in unthreshed grain stacked in a barn and says (op. cit.:590) that John Burroughs dug out a nest, composed of leaves and the fur of mice and moles, two or three handfuls in bulk, from a cavity the size of a hat, arched over with a fine network of tree roots.

Four instances in which the male as well as the female was present at a den containing young are cited by Hamilton (1933:328) and he gives some evidence, although not at all conclusive, that "adults customarily pair, or at least run together, at times other than the breeding season." No other writers remark on this matter. I doubt that adult ermines are associated in pairs for most of the year but such may be the case.

Mustela erminea arctica (Merriam)

Ermine

Plates , , , , , and

Putorius arcticus Merriam, N. Amer. Fauna, 11:15, pl. 2, figs. 1, 1a, and pl. 5, figs. 6, 6a, June 30, 1896.

Putorius (Gale) erminea, Coues, Fur-bearing animals, p. 109, 1877 (part).

Putorius richardsonii, Bangs, Proc. Biol. Soc. Washington, 10:16, pl. 1, figs. 3, 3a, pl. 2, figs. 3, 3a, and pl. 3, figs. 6, 6a, February 25, 1896 (part).

Putorius cicognanii alascensis, Osgood, N. Amer. Fauna, 19:43, October 6, 1900.

Putorius kadiacensis, Osgood, N. Amer. Fauna, 21:69, September 26, 1901.

Putorius audax Barrett-Hamilton, Ann. and Mag. Nat. Hist., 13(ser. 7):392, May, 1904, type from Discovery Bay, Ellesmere Island.

Putorius alascensis, Heller, Univ. California Publ. Zoöl., 5:345, March 5, 1910.

Mustela arctica arctica, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912; Dice, Journ. Mamm., 2:22, February 10, 1921.

Mustela arctica, Hall, Univ. California Publ. Zoöl., 30:420, March 19, 1929.

Mustela erminea arctica, Ognev, The mammals of U.S.S.R. and adjacent countries, 3:31, 1935; Hall, Proc. California Acad. Sci., 23:559, August 22, 1944; Hall, Journ. Mamm., 26:179, July 19, 1945.

Type.—Male, adult, skull and skin; no. 14062/23010, U. S. Nat. Mus.; Point Barrow, Alaska; July 16, 1883; obtained by John Murdock, original no. 1672.

The skull has a fracture, on the dorsal surface, extending from the anterior nares to the interorbital constriction and another fracture on the left margin of the nasal bone. The middle of the left zygomatic arch is broken away. Otherwise the skull is complete. Right incisor one, above and below, are missing. Otherwise the teeth are present and entire. The skin is in the brown summer pelage, well made, in a good state of preservation, and shows no obvious signs of fading.

Range.—Arctic regions of Alaska and western Canada from the Pacific Ocean to Smith Sound; from the northern limit of land south approximately to a line from Skagway through Ft. Goodhope, north shore of Great Bear Lake, south shore of Clinton Colden Lake, north shore of Baker Lake, west end of Wagner Bay to south end of Committee Bay. See figure on page .

Characters for ready recognition.—Differs from M. e. polaris in darker upper parts (Raw Umber rather than Buckthorn Brown) and less intensely colored underparts that are Sulphur Yellow, Colonial Buff or Primrose Yellow rather than Buff Yellow; from M. e. semplei, in males, in that hind foot more than 44 and basilar length more than 41 and in that females average larger, the skulls of females being only about 11 per cent heavier; from M. e. kadiacensis in hind foot more than 33 in females, zygomatic breadth amounting to more, rather than less, than distance between last upper molar and jugular foramen irrespective of sex; from M. e. richardsonii, alascensis, salva and initis, both sexes so far as known, by proximal two-thirds of under side of tail colored same as underparts rather than same as upper parts, and by zygomatic breadth amounting to more, rather than less, than distance between last upper molar and jugular foramen.

Description.—Size.—Male: Six adults from Tanana, Alaska, yield average and extreme measurements as follows: Total length, 336 (310-350); length of tail, 93 (84-105); length of hind foot, 49 (45-51).

Female: Five adults, one each from Alatna River, mountains near Eagle, Kamarkak in Alaska, Arctic Red River and Baillie Island in Canada, yield average and extreme measurements as follows: Total length, 285 (272-304); length of tail, 77 (68-95); length of hind foot, 39 (34-43).

Weight of 5 subadult males from Tanana is 206 (163-248) grams; adults would be heavier.

Color.—Winter pelage all white except tip of tail. Summer pelage with upper parts uniform in color and Raw Umber or darker (16n) of Ridgway and about tones 2 to 3 of Chocolate of Oberthür and Dauthenay, pl. 343, but in autumn some specimens have more light red than tones 2 or 3. Underparts Sulphur Yellow, Colonial Buff, or Primrose Yellow, often white on chin and insides of forelegs; color of underparts extends narrowly over upper lips, distally on posterior sides of forelegs onto antipalmar surface of forefeet, onto proximal two-thirds or three-fourths of underside of tail as length of tail is measured along tail-vertebrae, on medial sides of hind legs to a point between knee and ankle but reappears on antiplantar faces of toes and in some individuals is narrowly continuous onto toes; rim of ear in some specimens with short, white or pale hairs giving ears distinct whitish border; least width of color of underparts averaging, in adult males from Alaska, 65 (46-93) per cent of greatest width of color of upper parts. Black tip of tail in 5 males in winter pelage from Tanana averaging 84 (70-93) mm. which is 91 (75-107) per cent of length of tail-vertebrae.

Skull.—Male (based on 5 adult topotypes): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 3.5 (3.1-3.9) grams; basilar length 42.5 (41.8-43.3); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.

Female (based on 2 adult topotypes and 2 adults and 4 subadults from central Alaska): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.5 (1.2-2.0) grams; basilar length, 35.7 (34.5-37.0); length of tooth-rows more than length of tympanic bulla; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen (except in specimens from Ellesmere Island where two distances are approximately equal).

Cranial differences from Mustela erminea kaneii (which occurs on the Asiatic side of Bering Strait), in both males and females, are: larger size relatively as well as actually, broader except in mastoidal region where relatively (to basilar length) the width is less; preorbital part of skull broader as well as longer.

From kadiacensis differences in the skull of the male are: size less; 13 per cent heavier, relatively (to basilar length) narrower across interorbital region and zygomatic arches; tympanic bullae relatively as well as actually narrower. Judging by the single available adult female of kadiacensis, the skull of female arctica is larger in all parts measured, a fourth heavier, has tympanic bullae of almost twice the volume and the interorbital and preorbital regions, relative to the braincase, are much reduced in whatever plane measured.

Differences from richardsonii, additional to those noted above in the formal description of the skull, between the males, are: larger in all parts measured except length of tympanic bulla which is about the same; 42 per cent heavier; relative to basilar length, skull broader with preorbital part longer as well as broader; tympanic bullae more inflated posteriorly. The same differences prevail between females except that the skull is 36 per cent heavier and in arctica the length of the bulla is actually more (although relative to the basilar length less) and its greater inflation posteriorly is hardly perceptible. Differences from alascensis, additional to those indicated in the formal descriptions of the skulls of the two, in males, are: larger in every part measured; 95 per cent heavier; relative to the basilar length, skull broader with preorbital part longer as well as broader; measured at a point opposite the foramen lacerum anterius, the width of the pterygoid space is more, rather than less, than 40 per cent of its length. Excepting this difference in width of interpterygoid space, the same differences prevail between females, those of arctica being 56 per cent heavier.

Comparison with semplei is made in the account of that subspecies.

Skull indistinguishable from that of polaris.

Remarks.—The person who studies specimens of this subspecies finds labels inscribed with the names of naturalists well known to all readers of literature on the Arctic. Sir John Franklin, R. McFarlane, R. Kennicott, E. W. Nelson and R. M. Anderson are names which appear commonly. Of Alaskan specimens prepared according to modern methods, a large share was obtained by O. J. Murie and L. R. Dice.

The ermine was observed in the far north by early explorers and was mentioned in the literature, almost always under the name then used for the ermine of northern Europe and Asia. In 1896 Bangs misapplied to it the name richardsonii but Merriam in the same year corrected the application of this name and proposed as new for this weasel the name arctica, the name in use today. For almost 50 years after Merriam and Bangs wrote about it, arctica was treated, nominally at least, as a species distinct from its other relatives in both the Old- and New-World. The subspecific status of arctica was emphasized in 1944 (555) by the present writer in reporting in detail upon the specimens, of Mustela erminea, from Eastern Asia which were made available on loan by Professor B. S. Vinogradov and the late Anatol I. Argyropulo of the Leningrad Academy of Sciences. Specimens of Mustela erminea kaneii from the Asiatic side of Bering Strait and Mustela erminea arctica from the American side are distinguishable by slight cranial characters but in coloration and external measurements I can detect no differences. Merriam's (1896:16) mention of more golden-colored upper parts and darker underparts in American specimens than in erminea was the result of his comparison of Alaskan and northern European specimens. When Old World specimens from eastern Siberia, instead of from Europe, are used the differences mentioned by Merriam do not apply. Incidentally, many Siberian specimens have the white border, on the ear, which Merriam (loc. cit.) noted as a distinguishing feature of arctica. When Merriam named arctica he said (1896:15, 16) "Putorius arcticus . . . has heretofore been confounded with erminea or richardsonii. . . . It is interesting to find in this country an Arctic circumpolar weasel which, though specifically distinct, is strictly the American representative of the Old World erminea." Bearing in mind that Merriam's concept of species and subspecies (see Merriam, 1919:6) differed from that of nearly all modern systematists it is clear from his statement quoted above that he correctly understood the zoölogical relationship obtaining between the ermines of the Old and New Worlds.

Ognev (1935:31) seems to have been the first to use the name combination Mustela erminea arctica for Alaskan specimens. Thereby he expresses the view adopted here, namely that the American ermine is subspecifically but not specifically distinct from the Old World animal. Whether actual intergradation (crossbreeding) ever takes place across the narrow Bering Strait I do not know. I doubt that crossbreeding occurs but considering the Diomedes (islands), that might serve as a half way stopping point, and remembering Mr. Charles Brower's oral statement to me that he had seen tracks of ermine as far as 10 miles from the northern shore of Alaska out on the ice, the possibility must be granted of an occasional individual crossing from one side to the other of Bering Strait on the ice in winter or of being carried across when the ice broke up and drifted. If transfers of this kind occurred often one would expect ermines to occur also on Saint Lawrence Island where apparently they do not. The one skin (U. S. Nat. Mus. no. 259046) seen as labeled from there, my friend, Otto William Geist ascertained was imported as a skin with other furs from Siberia.

Ognev (op. cit.) who used the name combination Mustela erminea arctica for Alaskan specimens, applied it also to animals from Kamchatka. At the same time he recognized the animal from the eastern mainland of Siberia (as opposed to the peninsula of Kamchatka) under the name Mustela erminea orientalis Ognev 1928. Hall (1944:556) applied the earlier proposed name Putorius kaneii Baird 1857, to the animal on the eastern mainland of Asia and proposed the new name Mustela erminea digna for the ermine of Kamchatka. In comparing material of these two Asiatic races with topotypes and other specimens of M. e. arctica from Alaska, it seemed to me that the degree of relationship, one with the other, was about the same. M. e. digna has a slightly larger preorbital region than M. e. kaneii, and the skull is longer. In both of these particulars digna approaches closer to arctica. M. e. kaneii has longer tympanic bullae and a wider skull than digna and therein approaches more towards arctica than toward digna. As nearly as I can make out, digna and kaneii show a nearly equal degree of resemblance to arctica. Also the degree of difference between digna and kaneii is about the same as between either one of them and arctica. In view of the above considerations the ermines of the New and Old worlds are here regarded as only subspecifically distinct.

In the original description of Putorius audax (here regarded as inseparable from Putorius arcticus Merriam) Barrett-Hamilton erroneously designated the type locality as "Discovery Bay, North Greenland" whereas he should have written Grinnell Land [= Ellesmere Island of modern terminology] in place of Greenland. As reference to Nares (1877 and 1878) will readily reveal, Discovery Bay is near 65° W and 81° 40´ N, across Robeson Channel, to the west, from Greenland. The label on the type specimen and the specimen register in the British Museum of Natural History each designates the locality for this specimen, the type of audax, as Discovery Bay without mention of Greenland. The published accounts of Feilden (1878) and Nares (1877 and 1878) state that specimens of ermine were obtained at Discovery Bay. Probably H. C. Hart is the collector of the specimen; he was the naturalist attached to H. M. S. Discovery which wintered at Discovery Bay while H. W. Feilden was the naturalist attached to H. M. S. Alert which wintered a few miles southeast of Cape Sheridan, also on the eastern coast of Ellesmere Island.

It is true that from these ships a trip was made into Greenland and an ermine (only one individual it seems) was obtained there, but this individual was the type specimen of Mustela erminea polaris, in the account of which race something of the history of this specimen is given.

With the material available—and it is not entirely adequate—I can detect no features by which animals from the type locality of audax can be distinguished from typical arctica which latter name has priority.

Intergradation with richardsonii probably occurs completely across the continent. Intergrades here referred to arctica include those from Fort Goodhope. The one defective specimen from Lake Lebarge, Yukon, is not certainly identified as arctica and how far west of Teslin Lake the boundary-line between arctica and richardsonii should be drawn remains to be ascertained. The one specimen available from Hinchenbrook Island, no. 912 Mus. Vert. Zoöl., an adult female, is doubtfully referred to arctica because the damaged tympanic bullae appear to be no larger than in alascensis, and the size of the skull is more as in alascensis although intermediate between that race and arctica. Shape of the skull is more as in arctica. Possibly more nearly adequate material would show the existence on Hinchenbrook Island of an insular race differing in about the same degree from arctica of the mainland as does the insular kadiacensis. Nevertheless, the males from farther south at Cape Yakataga are in all respects arctica and this argues against near relationship to alascensis of the animal on Hinchenbrook Island. The three animals seen from Yakutat Bay are so young as not to display clearly the cranial characters of the subspecies but the extension of the color of the underparts onto the underside of the tail in them and also in the skin without corresponding skull from Glacier Bay, Alaska, is as in arctica, the race to which they are referred, and gives substantial basis for showing the geographic range of arctica as extending this far south along the Pacific Coast.

Specimens examined.—Total number, 281, arranged alphabetically by Districts and from north to south in each District. Unless otherwise indicated, specimens are in the collection of the United States National Museum.

Alaska. Point Barrow, 22 (1, 1, 1, 4, 7, 6); Flaxman Island, 3; Collinson Point, 1; Salirochet River, 1; Hulahula River, 1; 69°20´ & 141°, 1; Rampart House, 1; Yukon River, mouth of Porcupine River, 18; Alatna River, 30 mi. from mouth, 1; Koyakuk Riv., 16 mi. below Bettles, 4; Shelton, 1; Kruzamepa, 1; Tanana, 6; Boulder Creek, Chena River, 3; Fort Reliance, 4; Yukon River, 20 miles above Circle, 2; Mts. near Eagle, 42 (1); Snake River, Nome, 1; Nulato, 3; No[e]wikakat Riv., 1; Kantishna, 3; Fairbanks, 5 (1 20 mi. E and 1 33 mi. E); Richardson, 1; N. Fk. Kuskokwim R. at base of Mt. Sischo, 1; N. Fk. Kuskokwim R. at Junction with McKinley Fk., 1; Nenana Riv., mouth of Maurice Cr., 1; Ober Cr., trib. of Jarvis Cr., Delta Riv. region, 1; head of Savage Riv., near Jennie Cr., 1; Wonder Lake, 1; Bear Cr., 3; Unlakleet, 3; St. Michaels, 11; 125 mi. E and a little N of Knik, Cook Inlet, on S side Matanuska Range, 1; Hope, Cook Inlet, 1; Iak Lake, 1; head of Behring Riv., 1; Bethel, 2; Kenai Lake, 8; Kenai Peninsula, 13 (2); He[i]nchenbrook Island, 1200 ft., 1; Sunshine Point, Kaliekh River, Yakataga Dist., 1; Cape Yakataga, 3; Yakutat Bay, 3; Seward, 7; Seldovia, 22 (4); Homer, 1; Cape Elizabeth, 18; Akchookuk Lake, 1; Lake Weelooluk, 1; Kokwok Riv., 80 mi. up, 4; Nushagak, 1; Nushagak Riv., 1; Kolukuk, 1; Egooshik River at mouth, 1; Glacier Bay, 1; Becharof Lake, between Portage Bay and Becharof Lake, 1; Ugashik Riv., 4; Chignik, 7; East base Frosty Peak, 1; Pavlov Bay, 1; Mt. Pavlof, 1; Unimak Island, 2 (1).

District of Franklin. Cape Sheridan, 1; Discovery Bay, Ellesmere Island, 1 (type specimen of Putorius audax Barrett-Hamilton); Axel Heiberg Island, 1; Bache Peninsula, Ellesmere Island, 1; Bedford Pims Island, 4; Craig Harbor, 2; Cape Kellett, Banks Island, 1; Franklin Isthmus, 1; King William Island, 2.

District of Keewatin. Ualiak, Ogden Bay, 2.

District of Mackenzie. Baillie Island, 1; Franklin Bay, 1; Langton Bay, arm of Franklin Bay, 15 mi. S of, 1; Cockburn Point, 69°N, 115°W, 2; Dolphin and Union Strait, 1; Bernard Harbor, 2; Kent Peninsula, 4; Horton Riv., near Fort Anderson, 1; Fort Anderson, 6; Anderson River, 3; Barry Island, Bathurst Inlet, 1; Fort McPherson, 1; Peels River, 2; Arctic Red River, 8; Fort Good Hope, 6; Clinton Colden, 1.

Yukon. Kamarkak, 1; Herschel Island, 1; Lapierres House, 2; Forty Mile, L. T. Coal Cr., 4; head of Coal Cr., 1; Macmillan River, Forks, 1; 20 mi. W. Ft. Selkirk, 1; Slims River, near Kluane, 1; head of Lake Lebarge, 1.

Mustela erminea polaris (Barrett-Hamilton)

Ermine

Putorius arcticus polaris Barrett-Hamilton, Ann. and Mag. Nat. Hist., 13 (ser. 7):393, May, 1904.

Mustela erminea, Manniche, Meddelelser om Grønland, 45:80-85, 1 fig., 1910.

Mustela arctica polaris, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.

Mustela erminea polaris, Hall, Journ. Mamm., 26:179, July 19, 1945.

Type.—Probably female, skin only; no. 78. 6. 19. 11, Brit. Mus. Nat. Hist.; Gap Valley, 7-1/4 miles northeast Cape Brevoort, 82° N, 59° 20´ W, Northwestern Greenland; June 15 or 16, 1876; obtained by Lewis A. Beaumont.

The skin is in full, fresh summer pelage, fairly well stuffed except for the tail which is unstuffed; the whole is in a good state of preservation.

Range.—North coast, and east coast as far south as Turner Sound (between 69 and 70 degrees) of Greenland. See figure on page .

Characters for ready recognition.—Differs from M. e. arctica in lighter upper parts (near [j] Buckthorn Brown rather than Raw Umber or darker) and more intensely-colored underparts that are Buff Yellow rather than Sulphur Yellow, Colonial Buff, or Primrose Yellow; from M. e. semplei in color in same fashion as from arctica and in larger size of skull.

Description.—Size.—Male: One subadult and two adults (one ad. from Scøresby Sound and other two from Ymer Island) measure as follows, the average being given first: Total length, 318 (301, 320, 315); length of tail, 72 (69, 70, 73); length of hind foot, 46.5 (44, 46, 47).

Female: No measurements taken in the flesh available but hind foot, measuring 33.5 in the dried state and therefore approximately 35 in life.

Color.—As described in Mustela erminea arctica except that upper parts in summer near (j) Buckthorn Brown and tone 4 of Dark Fawn of plate 307 to tone 1 of Raw Umber of plate 301 of Oberthür and Dauthenay. Underparts Buff-Yellow. Least width of color of underparts averaging, in 3 males, 66 (57-72) per cent of greatest width of color of upper parts. Black tip of tail in same males averaging 71 (70-72) mm. which is 99 (99-104) per cent of length of tail-vertebrae.

The lighter-colored upper parts and more intensely yellow underparts are the distinguishing features of the subspecies polaris in comparison with other races of American M. erminea.

Skull.—Male (based on 5 adults from eastern Greenland): See measurements. As described in Mustela erminea richardsonii except that: Weight more (not recorded); basilar length, 41.3 (39.0-42.4); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.

Female (based on 2 adults, Turner Sund and Kap Hoeg): See measurements. As described in Mustela erminea arctica except that basilar length 36.8 (35.9, 37.8), and length of tooth-rows not more than length of tympanic bulla. Skulls of females not in hand when this comparison is written; only the recorded measurements are available.

To me the skull of polaris is indistinguishable from that of arctica. Therefore the comparisons made of the skull of arctica with those of other subspecies will apply also for polaris.

Remarks.—In view of the heretofore erroneous assignment of the type locality of Mustela erminea audax to Greenland, pains were taken to verify the statement by Barrett-Hamilton (1904:393) relative to the type specimen of polaris. Taking pains thus seemed the more worthwhile because in the specimen register at the British Museum of Natural History, there is written to the right of catalogue numbers 78-6 = 19 nos. 1-11, "Discovery Bay Presented by Mr. Hart Arctic Collection." This refers to no. 78.6.19.1. There are no ditto marks below but by implication this data applies also to nos. 1-11, which include the holotype of polaris. A label attached to the specimen does however give the locality as "Hall Land" "N Greenland" and another label has on it "Ermine, procured by Mr. Beaumont Greenland Lat 89° Long W 59-20." The 89° is obviously a mistake (on the label or in my transcription of it) for 82°.

Reference to Nares (1877:385) reveals that Lieutenant Lewis A. Beaumont, under date of June 15 and 16, 1876, wrote in his field journal as follows: "I shot an ermine." In the daily accounts of his journey from Discovery Bay on Grinnell Land [= Ellesmere Island], across Robeson Channel and along the north coast of Greenland to the west base of Mount Farragut near 50° 30´ W he mentions the ermine only this once. For several other kinds of animals, Beaumont mentions individuals seen or shot, often with the notation that this is the second, or third seen. This mention of a kind of animal whenever seen was in accordance with orders. On page of the Discovery Report (op. cit., 1877) in "General orders to sledging parties" by Captain G. S. Nares, Commanding the Expedition, we find ". . . note daily: IV State the animals seen and those shot." Reference to the map facing page of the (op. cit.) report reveals that on the 15th and 16th, camps were made by Beaumont in Gap Valley, each 7-3/4 miles northeast of Cape Brevoort, one camp on either side of the 82° line, and separated from each other by a distance of only 2-1/4 air line miles or 4-1/2 miles march according to his journal.

These several data, then, are the bases for designating the type locality of M. e. polaris, in the way that I have stated it at the beginning of this account of the subspecies.

The light-colored upper parts and more intensely yellow underparts well differentiate this subspecies from arctica or semplei. Intergradation is suggested by a skin, no. 1462, Copenhagen Zoological Museum, from Axel Heibergs Land, the color of the underparts of which agrees with that of specimens from Greenland. Also the color of the upper parts is decidedly nearer that of animals from Greenland than to that of specimens from Ponds Inlet, Tulican and Gifford River. No other specimens west or south of Greenland suggest intergradation. In Greenland itself, one adult, a female from Turner Sund, East Greenland, has the underparts no more yellowish than in some specimens from Melville Peninsula. This female is darker on the back than any one of the other 10 specimens from Greenland in summer pelage examined at the same time, but even so is not so dark colored as animals from Baffin Island or other islands to the west of Greenland.

The final summation of information about this subspecies would have been more precise if I had been able to have actually in hand, at the time of writing, specimens preserved in the Copenhagen Zoological Museum. The war made it impractical to secure the loan of these as previously planned. Even so, the measurements and notes on color that I obtained from this material, in 1937, in Copenhagen, suffice to prove that the subspecies polaris is well set off in color from the other American subspecies of Mustela erminea.

The best material of this subspecies is in the University Zoological Museum at Copenhagen, Denmark.

Specimens examined.—Total number, 35, arranged by locality from the western end of the north coast of Greenland, eastward and then southward down the east coast. Unless otherwise indicated, specimens are in the Universitetets Zoologisk Museum, Købnhavn, Danmark.

Gap Valley, 7-1/4 mi. NE Cape Brevoort, 82° N, 59° 20´ W, 1 (British Mus.); Dragon Point, 1; Danmarks Havn (Fjeldene ved Baadskjeret, 1; lille Fjeld, 1; Lyservig, 1; harefjeldets, 4; Rypefjeldet, 1; Baadskjeret, 1; Danmarkshavn, 3) 12; Christians Havn, 1 (not found on map); Shannon Island, 4; Germania Havn, 2; Claveringoen, 1; Carls Havn, 1; Myggbukta, 2 (British Mus.); Ymer[s] Island, 2 (Mus. Comp. Zool.); Kap Hoegh, Jamesonsland, 1 (Berlin Zool. Mus.); Scoresby Sund, 3; Turner Sund, 4.

Mustela erminea semplei Sutton and Hamilton

Ermine

Plates , , , , and

Mustela arctica semplei Sutton and Hamilton, Ann. Carnegie Mus., 21:79, February 13, 1932.

Mustela arctica labiata Degerbøl, Rept. 5th Thule Exped., 2 (no. 4):25, 1935, type from Malugsitaq, Melville Peninsula, Canada.

Mustela erminea semplei, Hall, Journ. Mamm., 26:179, July 19, 1945.

Type.—Male, subadult, skull and skin; no. 6470, Carnegie Mus.; Coral Inlet, South Bay, Southampton Island, Canada; October 8, 1929; obtained by George Miksch Sutton, original no. 3M.

The skull has two holes in it: one is immediately above the left canine, and the other (2 × 5.5 mm.) is 3 millimeters to the left of the median line at the juncture of the frontal and parietal bones. From this last mentioned hole a fracture extends back halfway to the lambdoidal crest. The tip of the left upper canine is broken off. Otherwise the skull is complete, and the teeth all are present and entire. The skin is well made and in fresh white winter pelage except for a trace of the old brown summer pelage on the back, on the tail, on the anterior borders of the ears, and in a spot 11 mm. long and 8 mm. wide on the nose.

Range.—Baffin and Southampton islands, Melville Peninsula and west side of Hudsons Bay as far south as Eskimo Point. See figure 25 on page .

Characters for ready recognition.—Differs from M. e. arctica, in that, in males, hind foot less than 44 and basilar length less than 41 and in that females average smaller, their skulls being only about 10 per cent lighter; from M. e. polaris in darker upper parts (Raw Umber rather than Buckthorn Brown) and less-intensely-colored underparts that are Sulphur Yellow, Colonial Buff or Primrose Yellow rather than Buff Yellow, and in lesser size in the same fashion as from arctica; from M. e. richardsonii, of both sexes, in that proximal two-thirds of under side of tail colored same as underparts rather than same as upper parts and by least interorbital breadth amounting to more, instead of less, than distance between glenoid fossa and posterior border of external auditory meatus.

Description.—Size.—Male: Ten adults and subadults, from Southampton Island, yield average and extreme measurements as follows: Total length, 282 (267-318); length of tail, 77 (59-87); length of hind foot, 40 (38-43).

Female: Four subadults from Southampton Island yield average and extreme measurements as follows: Total length, 271 (256-288); length of tail, 71 (69-74); length of hind foot, 35 (33-38).

Color.—As described in M. e. arctica except that least width of color of underparts averaging, in 7 males, 59 (45-81) per cent of greatest width of color of upper parts. Black tip of tail in 19 male topotypes averaging 72 (64-83) mm. which is 91 (75-122) per cent of length of tail-vertebrae.

Skull.—Male (based on 2 adults and 10 subadults from Southampton Island): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 2.0 (in one subadult) grams; basilar length, 37.5 (35.7-39.9); length of tooth-rows more than length of tympanic bulla; breadth of rostrum more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.

Female (based on 1 adult and 4 subadults from Southampton Island): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.35 (in one adult) grams; basilar length, 34.2; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more or less than (approximately same as) distance between last upper molar and jugular foramen.

In comparison with richardsonii, the skulls of males averaged smaller in every measurement taken except breadth of rostrum and interorbital breadth which are more, and zygomatic breadth and length of inner lobe of M1 which are approximately the same; skull about 20 per cent lighter; in relation to basilar length, preorbital region longer and broader in every part measured. Female averages larger, in every part measured; 23 per cent heavier; in relation to basilar length, every other measurement more. It is noteworthy that the skull of the male is smaller and the skull of the female larger than in richardsonii.

Differences from arctica are: Size less, in each sex; males about 40 per cent and females 10 per cent lighter; in males, skull more rounded in outline as viewed from above because zygomatic arches arise less abruptly from skull; in males tympanic bullae do not project so far ventrally from squamosal floor of braincase; with these exceptions, skull of semplei can be said to be a smaller edition of that of arctica.

From polaris, semplei differs, cranially, in the same way as from arctica.

Remarks.—There is a slight increase in size of ermines toward the north which probably is the result of intergradation between semplei and arctica. Specimens from the northern part of Baffin Island are larger than those from farther south. Specimens from the mainland west of Southampton Island may owe their smaller (than in arctica) size to intergradation with richardsonii almost as much as to intergradation with semplei.

Degerbøl's name Mustela arctica labiata was applied to specimens, which to me are indistinguishable from topotypes of Mustela arctica semplei, which latter name has three years priority. Degerbøl (1935:34) states that Malugsitaq, Melville Peninsula, is the type locality. He did not designate a type specimen. Reference to his account (op. cit.:26) shows that he lists five specimens from the type locality, or more precisely as "Malugsitaq, Lyon Inlet. 5 summer skins. ♂ ♂ June-July 1922. P. F., CN. 2262-2266." On labels attached to these specimens, "Lyon Inlet" is replaced with "Melville Peninsula." On July 28, 1937, Degerbøl and I together examined these specimens in his laboratory. Because no. 2262 is first mentioned I regard it as the type. It is a juvenal male, skull and skin, no. 2262 (20.5 1931.8), Univ. Zool. Mus. Copenhagen, obtained in June or July of 1922 by Peter Freuchen whose original number was / s 2324. The specimen is one of 5 males taken at the same locality by the same collector and they bear identical data as to date. They look to be of the same litter for all are roughly of the same size and each retains milk teeth.

Additional females, with external measurements carefully taken, are much needed from Southampton Island, because the available females are insufficient to show the degree of sexual dimorphism. If the meager data available be accepted, the difference in size between the two sexes is less than in other subspecies. My own feeling is that a better sample of females would show the secondary sexual difference in size to be more than available data indicate.

Specimens examined.—Total number, 183, arranged from north to south by islands, or regions attached to the mainland, and from north to south in each region or island. Unless otherwise indicated, specimens are in the Zoological Museum, University of Copenhagen, Denmark.

Baffin Island. Pond[s] Inlet, 8; (5); Tulukan (sometimes spelled Tulukat), 6; Cape Eglinton, 1; Gifford River, 2; Clyde, 3; head of Cumberland Sound, 1; Pangnirtung, 2; Kingnait Fiord, 1; Kikkulin Island, Cumberland Sound, 1; Blacklead Island, Cumberland Gulf, 1; merely Cumberland Gulf, 1; merely east Baffin Island, 34; Cape Dorset, 2; SW coast of Baffin Island, 1.

Melville Peninsula. Iglulik, 3; Pingerqalik, 2; Kingadjuaq, Amitsog, 3; Rae Isthmus, 3; Lyons Inlet, 13(9); M[N?] alugsitaq, Lyon Inlet, 5; Itibdjeriang, 2; Repulse Bay, 27 (22, 2); Drichetts Cove, Hurd Channel, 1; Gore Bay, 1; Haviland Bay, 1; Cleveland Harbor, Frozen Strait, 1.

Southampton Island and adjacent islands. Danish Island, 11; Vansittart Island, 4. Southampton Island: Coral Inlet, 19 (1, 18); Prairie Point, 1; Munnimunnek Point, South Bay, 5; Native Point, 1; Ranger Rim, 1; Koodloatok (not found on map), 1; merely Southampton Island, 1; Gore Bay, 1; Fox Channel, 2.

Mainland to west of Southampton Island. Cape Fullerton, 3 (1, 2); Chesterfield Inlet, 4 (1, 1); Tavane, 1; N of Wagner Inlet, 1; Eskimo Point, 1.

Mustela erminea kadiacensis (Merriam)

Ermine

Plates , , , , and

[Putorius arcticus] subspecies kadiacensis Merriam, N. Amer. Fauna, 11:16, June 30, 1896.

Putorius kadiacensis, Preble, Proc. Biol. Soc. Washington, 12:169, August 10, 1898.

Mustela kadiacensis, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.

Mustela erminea kadiacensis, Hall, Journ. Mamm., 26:179, July 19, 1945.

Type.—Male, subadult, skull and skin; no. 65290, U. S. Nat. Mus., Biol. Surv. Coll.; Kodiak Island, Alaska; April 25, 1894; obtained by B. J. Bretherton, original no. 304.

The skull lacks the basioccipital, part of the basiphenoid, the occipital region on the right side and the posterior part of the right tympanic bulla. The third, upper, left incisor is missing. Otherwise the teeth all are present and entire.

The white, winter skin is only moderately well stuffed but in a good state of preservation. The spring coat is appearing along the back. This coat is visible at only two places unless the hair be parted when the new brown pelage, which is coming in, can be seen all along the midline of the back.

Range.—Kodiak Island, Alaska. See figure on page .

Characters for ready recognition.—Differs from M. e. arctica in hind foot less than 33 in females and in zygomatic breadth amounting to less, instead of more, than distance between last upper molar and jugular foramen irrespective of sex.

Description.—Size.—Male: One adult and 3 subadults yield average and extreme measurements as follows: Total length, 341 (318-360); length of tail, 93 (86-102); length of hind foot, 47 (44-49).

Female: An adult measures: Total length, 258; length of tail, 70; length of hind foot, 31.

Color.—As described in M. e. arctica, except that least width of color of underparts averaging 54 (40-83) per cent of greatest width of color of upper parts. Black tip of tail in 3 males in summer pelage averaging 80 (70-90) mm. which is 85 (69-96) per cent of length of tail-vertebrae.

Skull.—Male (based on 2 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight 3.1 grams; basilar length, 42.6 (42.1-43.2); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus.

Female (based on one adult, no. 98042): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.2 grams; basilar length, 33.0; length of tooth-rows more than length of tympanic bulla.

Comparison with arctica has been made in the account of that subspecies. Although richardsonii and kadiacensis are described as having the zygomatic breadth less than the distance between the last upper molar and jugular foramen, the zygomatic breadth is considerably more in kadiacensis than in richardsonii; consequently the two dimensions are more nearly equal than in richardsonii. Except for being slightly narrower, the skull of kadiacensis is only a slightly smaller edition of that of arctica.

Remarks.—When naming the weasel from the mainland of Alaska as new, under the name Putorius arcticus, Merriam (1896:16) wrote: "A small form of arcticus occurs on Kadiak Island. . . . It is probably worthy of recognition as subspecies kadiacensis." The informality of this description possibly was in part due to the describer's recognition of the fact that the degree of difference between arcticus and the insular kadiacensis was slight. Specimens collected after Merriam proposed the name for the weasel of Kodiak Island show the animal there to be less different from arctica of the adjacent mainland than he thought; small size is the most pro nounced distinction of kadiacensis and Merriam's male type specimen is smaller than any of the five additional males saved from Kodiak Island since that time. Even so the differences fully warrant subspecific recognition, in my opinion, although kadiacensis is not a strongly differentiated race. More adult females are needed to ascertain the norm of form and size for that sex. If the one female known is typical, the difference from arctica is more pronounced in females than in males. The lesser size of kadiacensis can hardly be credited entirely to the effect of insularity, for animals from the southern part of the mainland, on Kenai Peninsula for example, are smaller than those from central and northern Alaska and provide evidence of intergradation of a sort between kadiacensis and arctica.

Specimens examined.—Total number, 9, all from Kodiak Island, Alaska, and unless otherwise indicated in the U. S. National Museum.

Karluk, 1 (Stanford Univ.); Kodiak, 7; Kodiak Island, 1 (Field Mus. Nat. Hist.).

Mustela erminea richardsonii Bonaparte

Ermine

Plates , , , , and

Mustela richardsonii Bonaparte, Charlesworth's Mag. Nat. Hist., 2:38, 1838.

Putorius cicognanii, Baird, Mamm. N. Amer., p. 161, 1858 (part).

Putorius richardsonii, Baird, Mamm. N. Amer., p. 164, 1858 (part-Halifax, N. S.).

Putorius (Gale) erminea, Coues, Fur-bearing animals, p. 109, 1877 (part).

Putorius richardsoni, Bangs, Proc. Biol. Soc. Washington, 10:16, February 25, 1896.

Putorius cicognani richardsoni, Merriam, N. Amer. Fauna, 11:11, June 30, 1896.

Putorius (Arctogale) cicognanii cicognanii, Bangs, Proc. New England Zoöl. Club, 1:18, February 28, 1899.

Putorius microtis Allen, Bull. Amer. Mus. Nat. Hist., 19:563, October 10, 1903. Type from Shesley, British Columbia.

Putorius arcticus imperii Barrett-Hamilton, Ann. and Mag. Nat. Hist., 13(ser. 7):392, May, 1904. Type from Fort Simpson, Mackenzie, Canada.

Putorius cicognanii richardsoni, Preble, N. Amer. Fauna, 27:231, October 26, 1908.

Mustela microtis, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912.

Mustela cicognanii mortigena Bangs, Bull. Mus. Comp. Zoöl., 54:511, July, 1913. Type from Bay St. George, Newfoundland.

Mustela cicognanii, Sheldon, Journ. Mamm., 13:201, August 9, 1932.

Mustela cicognanii richardsonii, Miller, U. S. Nat. Mus. Bull., 79:95, December 31, 1912; Hall, Univ. California Publ. Zoöl., 40:368, November 5, 1934.

Mustela cicognanii cicognanii, Hall, Canadian Field-Nat., 52:108, October, 1938.

Mustela erminea richardsonii, Hall, Journ. Mamm., 26:77, February 27, 1945; Hall, Journ. Mamm., 26:180, July 19, 1945.

Type.—Male, age unknown, skin; no. 43.3.3.4, British Museum of Natural History; probably from Fort Franklin, Canada; presented to British Museum on or before March 3, 1843; may be the type.

In September, 1937, when I searched in the British Museum for the skull, I found no trace of it nor mention of it in catalogues. The skin is in white, winter pelage, mounted on a pedestal. See under remarks for Mustela e. cicognanii for reasons for and reasons against regarding this specimen as the holotype.

Range.—Hudsonian and Canadian life-zones of the greater part of Canada from the Atlantic to the Pacific. See figure on page .

Characters for ready recognition.—Differs from M. e. arctica, polaris, semplei and haidarum, in both sexes, by proximal two-thirds of under side of tail colored same as upper parts rather than same as underparts, and interorbital breadth less, rather than not less, than distance between glenoid fossa and posterior border of external auditory meatus; from M. e. bangsi, in that, in both sexes, least width of color of underparts averages two-fifths rather than about a third of greatest width of color of upper parts, and in that skulls of males are a fourth heavier, basilar length averaging more than 40; from M. e. cicognanii, in both sexes, in that least width of color of underparts averages two-fifths instead of less than a third of greatest width of color of upper parts, in females by 20 per cent heavier skull (1.1 versus 0.92), in males by skull more, rather than less, than 1.9 grams, and basilar length more, instead of less, than 38; from M. e. invicta, in males, by skull more, instead of less, than 1.9 grams; mastoid breadth more, instead of less, than 19.9 mm.; depth of skull at anterior margin of braincase more, instead of less, than 12.4 mm.; in females, by same measurement of depth more, instead of less, than 10.1, and weight of skull averaging more, instead of less, than one gram; from M. e. fallenda in both sexes upper lips white rather than brown, in males, hind foot more than 41, basilar length more than 38.3, in females hind foot more than 29, basilar length more than 31.4, and breadth of rostrum amounting to less, instead of more, than 30 per cent of basilar length; from M. e. alascensis in males in that black tip of tail more than 43, total length more than 320, tympanic bullae more than 14 and longer than tooth-row rather than less than 14 mm. and sometimes shorter than tooth-row, females not individually distinguishable.

Description.—Size.—Male: Four adults (Fort Franklin, Fort Simpson, Mts. W Fort Nelson, and Govt. Hay Camp, Wood Buffalo Park) yield average and respective measurements as follows: Total length, 331 average (340, 325, 330, 328); length of tail, 93 (102, 91, 93, 87); length of hind foot, 45 (48, 43, 45, 44). Weight of 4 adults from the Belcher Islands is 175 (135-180) grams. Of 10 subadults from Belcher Islands it is 119 (92-137) grams.

Female: Three adults from Great Slave Lake (Willow River, Fairchild Point, and Fort Resolution) yield average and respective measurements as follows: Total length, 252 (237, 238, 282); length of tail, 69 (63, 60, 85); length of hind foot, 32 (31, 32, 34). Corresponding, average measurements for three adults from Glacier Lake are 240, 60, 32 and for 3 adults from the Athabasca Delta, 243, 65, 30. Weight of 8 subadults from the Belcher Islands is 69 (64-78) grams. Weight of adults would be more.

Color.—Winter pelage all white except tip of tail. Summer pelage with upper parts uniform in color and darker (16n) than Raw Umber, and about tones 3 to 4 of Chocolate of Oberthür and Dauthenay, pl. 343. Underparts Sulphur Yellow, Colonial Buff, or Primrose Yellow, often nearly white on chin and insides of forelegs; color of underparts extends narrowly over upper lips, distally on posterior sides of forelegs onto antipalmar faces of toes and sometimes over most of antipalmar surfaces of forefeet, on medial sides of hind legs to a point between knee and ankle but reappears on antiplantar faces of toes and in some individuals is narrowly continuous onto toes. Least width of color of underparts averaging, in a series of 12 males from the Athabasca Lake Region, 40 (25-54) per cent of greatest width of color of upper parts. Black tip of tail averaging 56 (45-63) mm. in 5 adult males from same region and thus 60 (48-70) per cent of length of tail-vertebrae.

From arctica, polaris, semplei and kadiacensis, richardsonii differs in: Color darker; ventral side of tail same color as upper parts; light-colored underparts a fifth narrower; black tip of tail by actual measurement a fifth shorter and averaging less than two-thirds rather than more than four-fifths of length of tail-vertebrae. From cicognanii, richardsonii differs in that the underparts are a fourth wider and in some specimens more brightly colored. The width of the underparts is likewise a fourth more than in bangsi. In invicta the underparts are not so brightly colored as in some specimens of richardsonii. From fallenda, richardsonii differs in that the upper parts often are lighter colored, upper lips white rather than colored like upper parts, and underparts as wide again. In comparison with alascensis, the black tip of the tail averages three-fifths rather than a half of length of tail-vertebrae.

Skull.—Male (based on 6 adults from 3 miles south of Big Island, Great Slave Lake): See measurements and plates -; weight, 2.5 (2.1-2.9) grams; basilar length, 40.9 (39.6-43.7); length of tooth-rows less than length of tympanic bulla; breadth of rostrum measured across lacrimal processes less than a third of basilar length; interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth less than distance between last upper molar and jugular foramen.

Female (based on 4 adults: from Willow River, 1; Fort Resolution, 1; Athabasca Delta, 2; and 2 subadults, one from 3 mi. S Big Island and one from 15 mi. above Smith Landing): See measurements and plates -; weight, 1.1 (0.9-1.4) grams; basilar length, 33.1 (31.5-34.2); length of tooth-rows less than length of tympanic bulla; breadth of rostrum less than 30 per cent of basilar length; interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth less than distance between last upper molar and jugular foramen.

The skull of the female averages 56 per cent lighter than that of the male.

Comparison of the skull with that of arctica, polaris, semplei, kadiacensis, haidarum, cicognanii, bangsi, invicta, fallenda, and alascensis is made in the accounts of those subspecies.

Remarks.—M. e. richardsonii has the most extensive geographic range of any American race of erminea, is centrally located with respect to the other races, is more abundantly represented by study specimens in zoölogical collections than any other race, and is a sort of average for the species as a whole in most structural features. Therefore richardsonii is used as a standard of comparison and accordingly is more fully described than any one of the other races each of which by reference to richardsonii is described in comparative fashion. This comparative description has the virtue of more clearly indicating differences between subspecies and also makes for brevity.

John Richardson, Bernard R. Ross, and names of their companions, as written on the labels of the older specimens recall to the student's mind early explorations of the north country. Edward A. Preble obtained important specimens at several places and in recent years J. Kenneth Doutt and G. G. Goodwin have made the reviser's work easier by preparing specimens in series from areas not previously well represented.

The nomenclatural history of this subspecies begins with references in the literature that identify the animal as the Old World species, Mustela erminea—an identification which the study here reported upon shows to have been correct in the specific, although not in the subspecific, sense. Richardson, for example, in his "Fauna Boreali-Americana" published in 1829 so identified the animal. In 1838, Bonaparte, basing his description on Richardson's account of 1829, proposed the new name richardsonii. Richardson himself, the following year in the "Zoology of Beechey's Voyage," accepted Bonaparte's name and it has been applied to the animal in the central part of the northern timber-belt of North America ever since, except as authors used the name Mustela erminea in the belief that richardsonii was not distinct from erminea.

The north and south boundaries of the range assigned to richardsonii varied according to the notions of the particular writer who was employing the name. Until Merriam in 1896 named arctica as distinct, animals from the far north were generally included under the name richardsonii along with populations to which the latter name now is applied. Because richardsonii grades gradually into the smaller cicognanii of more southern occurrence the boundary between the two has been set farther north by one writer and farther south by another, depending probably upon what the writer felt was the halfway point in size. This point of course depended upon the samples selected as typical of richardsonii on the north and cicognanii on the south. Because Bangs, in 1896, took as representative of richardsonii the far northern and hence large-sized animals (now separated as M. e. arctica), his halfway point in size between them and the small cicognanii of New England naturally fell farther north than it would have had he used as representative of richardsonii specimens from places south of the range of arctica.

In 1903 J. A. Allen proposed the name Putorius microtis for a specimen from Shesley, northwestern British Columbia, a place approximately 50 miles northwest of Telegraph Creek. Considering the great disparity in size between this one specimen and the other larger specimens of normal size, from the general region, available to Allen at that time, it is not surprising that he thought two full species were represented. In 1943 when G. G. Goodwin called to my attention two males, as small as the type of microtis and taken by him approximately 300 miles east of Shesley, in the valley between the Musqwa and Prophet rivers, I for a second time examined all available specimens and data with the possibility in mind that microtis was a species or subspecies distinct from M. e. richardsonii, but again concluded that only one subspecies was involved because no character except size was found to distinguish the large from the small individuals of a given sex and there are, preserved from northern British Columbia, individuals of intermediate size. Putorius microtis Allen seems to have been based on an individual of M. e. richardsonii near the lower limit of size for that subspecies and microtis is regarded as a synonym.

Barrett-Hamilton in 1904 named the animal at "Fort Simpson, British Columbia" Putorius arcticus imperii. Preble (1908:232) pointed out that Fort Simpson on the Mackenzie undoubtedly was the place intended, and arranged imperii as a synonym of M. e. richardsonii. The type specimen of imperii was stated to have been received from B. M. Ross who is known to have collected specimens, including specimens of this species (now in U. S. Nat. Mus.), at Fort Simpson on the Mackenzie. I know of no Fort Simpson in British Columbia. If, as seems improbable, Port Simpson, British Columbia, was the place that Barrett-Hamilton intended to designate (where so far as I know Ross did not collect), the name imperii still would seem to be a synonym of richardsonii because richardsonii seems to be the race of weasel at Port Simpson. In proposing the name Putorius arcticus imperii, Barrett-Hamilton stressed that the weasel, which he was naming, was a subspecies of P. arcticus, gave characters which applied perfectly to richardsonii but made no reference to richardsonii. Barrett-Hamilton did not refer to richardsonii possibly because he relied on Merriam's classification of 1896 wherein richardsonii is treated as a species distinct from arctica. Merriam, it will be remembered, held that slight degree of morphological difference rather than intergradation was the criterion for subspecies. Although I have no record of having examined the type specimen of imperii I have but little hesitancy in treating it as a synonym, and would have no hesitancy at all in so doing if the type was certainly known to have been obtained at Fort Simpson on the Mackenzie.

The name Mustela cicognanii mortigena Bangs, 1913, proposed for the ermine of Newfoundland, is placed as a synonym of richardsonii only after repeated, detailed comparisons. In advance of study I supposed that the isolation of the ermine, in Newfoundland, had contributed to its differentiation, which, however, the original describer, Bangs, indicated was slight. Bangs was a careful worker and I am confident that the differences he described really existed between his specimens. Material more nearly adequate than he had from the mainland, shows the males, so far as my measurements and comparisons go, to be in nowise different from those in Newfoundland. Females in Newfoundland may have, on the average, slightly longer hind feet than on the opposite mainland but I am not certain that they do and even if there is a slight difference in this regard as suggested by available data, I think it insufficient basis, alone, for according subspecific status to the insular animal.

The name richardsonii was based by Bonaparte on Richardson's description which in turn was drawn from a specimen taken at Fort Franklin, that thus becomes the type locality. It is fortunate that Preble, in 1903, succeeded in taking specimens there because the place is near the belt of intergradation between arctica and richardsonii. Of Preble's two adult males (see Preble, 1908:232) I have examined no. 133847, which is in transitional pelage and therefore gives no clue in so far as coloration is concerned, as to affinities with arctica versus richardsonii. Specimens in the summer pelage are much to be desired from Fort Franklin. Regardless of what their coloration may be, specimen no. 133847, in external measurements and most certainly in cranial features is of the race to the south and not the race that Merriam named arctica. Because all specimens from localities to the south of Fort Franklin likewise differ from arctica of the barren grounds, considerable additional confidence is felt in allocating the name richardsonii to the animal which ranges from Fort Franklin southward rather than to the one, here designated arctica, that occurs to the northward of Fort Franklin.

Although in most structural features richardsonii is a sort of average for the American races of the species, it is the extreme in high degree of sexual dimorphism. The difference in size between the males and females is greater than in any other race except possibly M. e. kadiacensis in which so little is known of the female that the difference between the two sexes cannot be accurately judged. It will aid in understanding the high degree of secondary sexual difference in richardsonii to visualize two kinds of weasels distributed over the northern half of the continent, thinking now of the geographic area in America occupied by the whole species Mustela erminea of which the subspecies richardsonii is only a part. One of the two kinds of weasel is the male ermine and the other the female. The decrease in size of the male, as measured by the weight of the skull, is in the ratio of 7 in the north to 2 in the south. This decrease is gradual whereas the corresponding decrease from 3 to 1 in the female is not gradual; half of the decrease in the female occurs in the short north to south distance comprised in the belt of intergradation, along the northern boundary of richardsonii, between it and arctica. As a result richardsonii is composed of females with medium sized skulls and males with relatively large skulls, the ratio by weight being approximately 5 to 2. The disproportion in races of ermines both to the north and to the south is less. Actually in the north (arctica) the approximate ratio by weight is 2-1/3:1; in richardsonii, 2-1/2:1; in the south (muricus), 1-2/5:1. Indicated in still another way in richardsonii the skull of the female is 56 per cent lighter than that of the male and the skull of the male is 127 per cent heavier than that of the female. Intergradation with races whose ranges border on that of richardsonii is complete. On the northern boundary of the range of richardsonii along the western shore of Hudsons Bay for perhaps a hundred miles north of Eskimo Point, there are intergrades with arctica. As judged by their lesser size, individuals of this population are influenced by the semplei-stock. Otherwise, intergradation on the northern boundary, with arctica, is abrupt whereas intergradation at the south, between richardsonii and cicognanii, is gradual. Intergradation is similarly gradual between richardsonii on the one hand and bangsi and invicta on the other. By speaking of the intergradation as abrupt, it is intended, in this instance, to indicate that in a relatively narrow belt, between the geographic ranges of arctica and richardsonii, ermines intermediate in color-pattern, shape of skull, and size, bridge the gap between the ermine of the tundra (arctica) and that in the forest belt (richardsonii). It may be added that the degree of difference between the two subspecies just mentioned is approximately twice as much as between richardsonii and cicognanii. The intergradation between cicognanii and richardsonii is gradual. By gradual it is meant that the change from one kind to the other is achieved in a wider area where ermines from locality A do not differ appreciably from those taken at, say, locality B, 50 miles farther south, although ermines from A and those from a third locality, C, say, 130 miles south, clearly show differences indicative of geographic variation.

Specimens examined.—Total number, 1035, as follows. Arranged alphabetically by provinces and districts and from north to south in each province or district. Unless otherwise indicated, specimens are in the United States National Museum.

Alberta. 15 mi. above Smith Landing, 2; Fort Smith, 2 (1); Smith Landing, 2; LaButte, Fitzgerald, 1; Egg Lake, 15 mi. NW Ft. Chippewyan, 4 (2); Lobstick Island, near Ft. Chippewyan, 1; Athabasca Delta, 9 mi. above mouth of main branch, 1; Athabasca Delta, Long Creek, 1 mi. W of main branch, 2; Ft. Chippewyan, 1; Peace Point, 1; 18 mi. below Peace Point, 1; Embarass River, 7 (4); Athabasca River, 1; Ft. McMurray, 1; Athabasca River, Middle Rapid, 2; 60 mi. above Grand Rapids, 1; Boiler Rapid, 1; Entrance, 3; St. Albert, 2.

British Columbia. Fort Halket, 1; Shesley, 1; Dorothy Lake, Mts. W of Ft. Nelson, 4000 ft., 3; valley between Musqwa and Prophet rivers, 3800 ft., SW of Ft. Nelson, 2; Sikanni Chief Riv., 1; Telegraph Creek, 7 (6); head of Bad River, 2350 ft., on lake, 1; Six Mile, 5; Tuchodi Lake, 2; Iskoot River, 2; Level Mtn., 1; head of Tatletuey Lake, 12 mi. W Thudade Lake, 2; Robb Lake District, 5; Ft. Grahame, 12 (2); Sustut Mts., on trib. Sustu Riv., 25 mi. SE Thudade Lake, 2; Laurier Pass, 1; Omineca Mts., 1; Point Creek and Clearwater River, 2; Kispiox Valley, 23 mi. N Hazelton, 5; Hazelton, 3; NW arm Tacla Lake, 7; N end Babine Lake, 1; Pt. Simpson, 1; Metlakatla, 1; Stuart Lake, 27; S Fk. Salmon Riv., 1; mouth Salmon Riv., 1; Vanderhoof, 4; Wistaria P. O., near Burns Lake, 1; Kruger Lake, 9; Indianpoint Lake, 23; Quesnel, 1; Ahbau Lake, 3; Isaacs Lake, 6; Beaver Pass, 56; Lightning Creek, 54; LaFontaine, 16; Barkerville, 1; Barkerville District, 34; Swift River, 27; Cunningham Creek, 34; Itcha Mts., 1; Anahim Lake, 1; Chezacut Lake, 8; Kleena Kleene, 18; 158 mi. House (Cariboo on labels), 3; Rivers Inlet, 6 (5; 1); Horse Lake, 4; Kingcome Inlet, 8; Loughborough Inlet, 7; McGillivary Creek, 1; Camel Back, Pemberton Meadows, 1; Arrow Rapids, mainland opposite Stuart Island, 1; Butte Inlet, 9; Green Lake, 1; Mt. Whistler, 1; Alta Lake, 2 (1; 1); Mons, 1.

Keewatin. Foot of Baker Lake, 1.

Labrador. Okak, 3; Nain, 22 (11; 11); Hopedale, 24; Kippokak Bay, 7; Ailik, 1; Makkovik, 26; Labrador, 55° N, 3; Hamilton Inlet, 2; NW River Post, interior Labrador, 5; Cartwright, 5; Paradise, 12; Sandwich Bay (Muddy Bay, 6; North River, 6), 12; Battle Harbor, 1; St. Marys River, 3; Black Bay, 16 (15; 1); Lanceau Loup, 17 (1).

Mackenzie. Ft. Franklin, 1; Ft. Rae, 12; Fairchild Point, 6; Fort Simpson, 10 (2); Hot Springs (61°, 125°), 1; Willow River, near Ft. Providence, 1; 35 mi. N Big Island, 7; Big Island, 9; 3 mi. S Big Island, 7; Ft. Resolution, 9; 100 mi. N Ft. Smith, 2; 75 mi. NW Ft. Smith, 1; Ft. Liard, 2; Sucker Creek, 4; Govt. Hay Camp, Wood Buffalo Park, 2.

Manitoba. Egg Is., Rabbit Point, 1; Ft. Churchill, 1; Ft. York, W Hudsons Bay 57° N, 1; Oxford House, 11; Gypsumville, 1; Lake St. Martin.

New Brunswick. Restigouche County: Bird Bait, north Camp, 6 mi. NE Nictau Lake, 2; Red Brook, Tobique River, 1. Victoria County: Trousers Lake, 3. Glouchester County: Youghall, 1; Miramichi Road, 15 mi. from Bathurst, 13. York County: Scotch Lake, 2.

Newfoundland. Nicholsville, 3; Bay St. George, 48 (26; 2; 1); Codroy, 9 (7; 2).

Nova Scotia. Victoria County: Cape North, 2. Inverness County: Fizzleton, 3. Richmond County: St. Peters, 1. Pictou County: Glengary, 1. Guysborough County: East Roman Valley, 5. Kings County: Wolfville, 5 (3, 2); near Wolfville, 1. Halifax County: Hammond Plains, 1. Annapolis County: Annapolis Royal, 1. Digby County: Digby, 3. No locality more definite than Nova Scotia, 3.

Ontario. Severn River, 1; R. C. Mission, Yellow Creek, near mouth of Albany, 2; Ft. Albany, 4; Charlton Island, 1; Moose Factory, 10 (7; 3); Abitibi, 1.

Quebec. Fort Chimo, 10; Ungava Forks, 1; Belcher Islands, Hudsons Bay (Tukarak Island, 29; Eskimo Harbor, 2; Innetalling Island, 1; S tip Gibson Peninsula, 2; Flaherty Island, 1), 35; Cairn Island, Richmond Gulf, 2; Manitounuk Sound, 4; about 15 mi. S Great Whale River, 1; Ft. George, 1; Charlton Island, 1; Waswonaby Post, 1; Mistassinnay Post, 3; Godbout, 36; Mt. Albert, 7 (4; 3); St. Anne River, 1500 ft., 1; Ste. Anne des Monts, 3; "Federal Mine," 1; Berry Mountain Camp, 1; Berry Mountain Brook, 1; Cascapedia River (Middle Camp, 2; Tracadie, 2; Square Forks, 1), 5.

Saskatchewan. Poplar Point, Athabasca Lake, 1; Fair Point, Athabasca Lake, 1; Emma Lake, 1; Harper Lake, 2; Livelong, 3; Fairholme, 2; Touchwood Hills, 2; Indian Head, 1.

Yukon. Hoole Canyon, 1; Teslin Lake (30 mi. N of, 1; Lake itself, 1; "near" the lake, 1; Mts. "near," 2; Snowden Mts., 2; Teslin Post, 2; Eagle Bay, 1; Morley Bay, 2; Nisutlin River, 1; Nisutlin Flats, 2; Wolf River, 1; Wolf Lake, 5), 21.

Mustela erminea cicognanii Bonaparte

Ermine

Plates , , , , and

Mustela cigognanii [sic.] Bonaparte, Charlesworth's Mag. Nat. Hist., 2:37, 1838.

Putorius vulgaris, Emmons, Quadrupeds of Massachusetts, p. 44, 1840.

Mustela pusilla DeKay, Zool. of New York, Pt. 1, Mammalia, p. 34, pl. 14, fig. 1, 1842. Type from New York State.

Putorius pusillus, Audubon and Bachman, Vivip. Quadrupeds of N. Amer., 2:100, pl. 64, 1851 (pl. 1846) and erroneously labeled Mustela fusea, as pointed out on page of text.

Putorius cicognanii, Baird, Mamm. N. Amer., p. 161, 1858.

Putorius richardsoni cicognani, Bangs, Proc. Biol. Soc. Washington, 10; 18, figs. 4, 4a of pls. 1 and 2, and pl. 3, figs. 2, 2a, February 25, 1896 (part).

Putorius cicognani, Merriam, N. Amer. Fauna, 11:10, pl. 2, figs. 3, 3a, 4, 4a and pl. 5, figs. 2, 2a, June 30, 1896.

Mustela cicognanii cicognanii, Miller, U. S. Nat. Mus. Bull., 79:95, December 31, 1912; Bishop, Journ. Mamm., 4:26, February 9, 1923.

Mustela cicognanii, Jackson, Journ. Mamm., 3:15, February 8, 1922.

Mustela erminea cicognanii, Hall, Journ. Mamm., 26:77, February 27, 1945; Hall, Journ. Mamm., 26:180, July 19, 1945.

Type.—No type specimen designated; type locality, eastern United States.

The restriction of the type locality from the general region of northeastern North America, as given by Merriam (1896:10) to the less inclusive area of the eastern United States as earlier given by Bangs (1896:18) is supported by Bonaparte's remarks in connection with the proposal of the name cicognanii. He says (1838:37-38) "During my stay in the United States, I only saw a small species of Mustela, very common throughout the Union . . . ." This animal constituted basis for the name cicognanii which name, he points out, is bestowed in order that the Americans ". . . should have constantly under their eye, this very common little animal, as the perpetual memorial . . ." to the Italian Governmental representative ". . . who, for upwards of fourteen years had served, in diplomatic and commercial concerns, . . . two countries, . . . so different . . . as the Roman and the United States. . . ." Clearly he had in mind principally, if not exclusively, the animal of the United States.

Range.—Transition and higher life-zones of northeastern United States south to Connecticut, central Pennsylvania and extreme northeastern Ohio; in Quebec and Ontario westward from the latitude of central Maine to Lake Nipigon and Lake of the Woods. See figure on page .

Characters for ready recognition.—Differs from M. e. richardsonii of both sexes, in that least width of color of underparts averages less than a third rather than two-fifths of greatest width of color of upper parts, in males skull less, instead of more, than 1.9 grams and basilar length less than 38, in females by 16 per cent lighter skull (0.92 versus 1.1 grams); from M. e. bangsi, in males hind foot less instead of more than 40, linear measurements of skull averaging 11 per cent less (depth of skull at plane of molars 10.0 versus 11.4), in females averaging smaller, hind foot 30 versus 32 and depth of skull at plane of molars 8.6 versus 9.1.

Description.—Size.—Male. Seven adults and subadults from New York and Pennsylvania, yield average and extreme measurements as follows: Total length, 266 (240-295); length of tail, 74 (66-80); length of hind foot, 36 (33-39). Hamilton (1933:294) gives the weight of 31 adults from New York as 81 (66-105) grams.

Female: Twelve adults and subadults from Maine and the area south to central Pennsylvania, yield average and extreme measurements as follows: Total length, 243 (225-260); length of tail, 63 (55-72); length of hind foot, 29.8 (26-32). Hamilton (1933:294) gives the weight of 15 adults from New York as 54 (45-71) grams.

Color.—As described in Mustela erminea richardsonii except that underparts in summer Marguerite Yellow or even more whitish; least width of color of underparts averaging, in adult males from New York and Pennsylvania, 29 (27-32) per cent of greatest width of color of upper parts. Black tip of tail in same series averaging 42 (30-51) mm. which is 57 per cent of length of tail-vertebrae.

Skull.—Male (illustrated by 4 adults in table of cranial measurements, which see): See plates -. As described in Mustela erminea richardsonii except that: Weight, 1.5 (1.2-1.7) grams; basilar length, 35.7 (33.8-37.6).

Female (illustrated by adult and subadults recorded in table of cranial measurements, which see): See plates -. As described in Mustela erminea richardsonii except that: Weight of 2 subadults, 0.92 (0.86-0.98) grams; basilar length, 32.4 (31.4-33.3).

The skull of the male, in linear measurements, is approximately 13 (12-16) per cent smaller and 40 per cent lighter than in M. e. richardsonii. In relation to the basilar length, the skull averages slightly narrower, slightly shallower as measured in the vertical plane touching the posterior borders of the last upper molars, and the preorbital part is slightly longer. In skulls of females of cicognanii, linear measurements average 3 (0-6) per cent less, the weight is 16 per cent less and the teeth are 5 per cent shorter. In relation to the basilar length, measurements of the skull are approximately the same or slightly less in cicognanii.

In comparison with bangsi, the male sex in linear measurements of the skull and teeth averages 11 per cent less than in bangsi from Aitkin, Minn., and 6 per cent less than in bangsi from Elk River, but in relation to the basilar length the preorbital region is larger. The weight is approximately a fourth less. In females the measurements average less, some being the same, and in relation to the basilar length, the bullae are shorter and the skull is shallower. The weight is about the same.

Remarks.—In January, 1838, in Charlesworth's Magazine of Natural History, C. L. Bonaparte proposed for three kinds of American weasels the names Mustela cicognanii, Mustela richardsonii and Mustela longicauda.

In this paper Bonaparte indicates that he previously had written (for his Iconografia della Fauna Italica ...) an account of Mustela cicognanii using this same name. Fasciola XXII of the Iconogr. d. Fauna Italica, presenting his account of Mustela, like the English paper was published in the year 1838. In his article in Charlesworth's Magazine, Bonaparte refers to his book published [used the past tense] in Rome but whether it actually appeared first I am unable to determine and hence am uncertain which of the two constitutes the original description.

Reference to the Italian account suggests as basis for the name M. cicognanii, (1) specimens possibly seen in the United States by Bonaparte, or (2) Godman's published account of the animal.

In the English publication, however, Bonaparte actually says that (1) he saw the small species in the Union [= United States]. Also, he (2) mentions his earlier written Italian account, (3) mentions that "all the [American?] naturalists" used the name M. vulgaris for this animal, (4) incidentally mentions Godman's account, and (5) in naming two other American species cites accounts of them by Richardson. Also, Bonaparte in this English article makes clear that when he wrote [not necessarily published] his Italian paper he did not know of the existence of two of the three American species.

In the register of mammals at the British Museum of Natural History, there appears:

43.3.3.3 Mustela longicauda Bonap N Amer. presented by Dr. J. Richardson
4 Mustela Richardsonii Bonap "
5 " Cicognanii Bonap "

To the right of these entries there appears, in three lines, the notation: "The three specimens examined by Prince Canino on which he established the three species."

Every part of each of the above entries is in the hand writing of J. E. Gray, in charge of the collections from 1824 to 1840 and associated with them as Keeper until 1875. The three specimens are in good condition considering their age. The catalogue or register number shows, among other things, that they were entered in the register on March 3, 1843.

Questions which might occur to anyone are:

(1) Was there a type specimen of Mustela Cicognanii Bonaparte? If so is it no. 43.3.3.5?

(2) If there was no type specimen was there a type locality? If so what is it?

Among other things that may have bearing on these questions, are these: Bonaparte in Charlesworth's Magazine appears to base the two names Mustela Richardsonii and Mustela longicauda on Richardson's published account of Mustela erminea. At any rate immediately following each of the two names, Bonaparte writes "Nob. (M. erminea Rich. F. Bor. Amer.)." Bonaparte's other, first newly proposed name, Mustela Cicognanii, in Charlesworth's Magazine has following it only "Nob. North America," although in a paragraph above he did point out that this was the animal which all naturalists, at the time he was in America, considered as M. vulgaris.

Turning to Richardson's account (Fauna Boreali Americana, ... Quadrupeds, pp. 45-47. 1829) one finds that he recognized two species, M. vulgaris and M. erminea. Of the first he gives measurements "of an old female killed at Carlton House." Of the second species he distinguishes two varieties, the first represented by a specimen, of which he gives measurements, "killed at Fort Franklin, Great Bear Lake" and, the second variety "of a larger size, having a longer tail and longer fore-claws" he indicates the size of by giving measurements of a specimen taken "in the neighborhood of Carlton House."

The last variety is clearly the basis of Bonaparte's M. longicauda. The specimen from which Richardson took his measurements I have been unable to locate [no. 43.3.3.3 in the British Museum, appears to be another specimen, although of the same subspecies and provided by Richardson].

The first variety of Richardson's Mustela erminea, clearly is the basis of Bonaparte's M. Richardsonii. The specimen from which Richardson took his measurements may well be no. 43.3.3.4 now preserved in the British Museum of Natural History, but I could not be certain about this.

Richardson's M. vulgaris is accompanied by measurements of a female which I have ascertained to my full satisfaction is the identical specimen now bearing catalogue number 43.3.3.5 said by Gray to be the specimen on which Bonaparte based his name Mustela cicognanii.

Gray probably saw his guest, Bonaparte, at work on these weasels and Gray's own written indication perhaps should be accepted at its face value. I found only 4 Richardson specimens of North American weasel in the British Museum in 1937 and it is conceivable that Bonaparte, 100 years before, actually had at hand only one specimen each of two kinds and 2 specimens of the third. This I think is not an important consideration, though, for Gray says just which specimens did serve as basis for Bonaparte's names and there is only one specimen for each name according to Gray.

But I wonder if a type specimen can be made in this way? That is to say, after a name is published in a manner which makes it available, and if two or more specimens of the kind of animal involved, were, or may have been, available to the describer, can a person, even the author, himself, make a type specimen by saying that one particular specimen is beyond doubt the specimen on which a given name was established even though no particular specimen was designated in the original description? I incline to the view that a specimen so designated would at most be only a lectotype, unless it were a cotype.

However, if a holotype can be made by action such as Gray took, then (1) is no. 43.3.3.3 the type specimen of Mustela longicauda Bonaparte and, (2) is no. 43.3.3.4 the type specimen of Mustela Richardsonii Bonaparte?

Incidentally, Mustela longicauda Bonaparte whether based on no. 43.3.3.3 or on Richardson's account will continue in its present application. The same is true of Mustela richardsonii. If the basis of Mustela cicognanii Bonaparte [the diagnosis in the Iconografia d. Fauna Italica ... makes it clear that the name applies to the short-tailed species] was a weasel from the eastern United States or a description of a weasel or weasels from there, the name will continue in its present application. If, instead, the name is based on no. 43.3.3.3 (from Carlton House, Saskatchewan) or on Richardson's account of M. vulgaris, the name will apply to a different subspecies (now called richardsonii and richardsonii will fall as a synonym of cicognanii) and the ermine of the eastern United States will take the next available name. Bonaparte probably named (in manuscript at least) cicognanii before he ever saw the specimen in the British Museum. This is indicated by his statement in Charlesworth's Magazine (1838:37) that "I have now [Italics mine] found two [other] American species. . . ." Whereas the names richardsonii and longicauda are based on Richardson, the name cicognanii, even if it dates from the account in Charlesworth's Magazine, appears to have a composite basis composed at the very least of (1) animals seen by Bonaparte in the United States, and (2) those called vulgaris by some other authors. Conceivably the specimen no. 43.3.3.3 in the British Museum, was part of the basis. From the nature of the case it can be argued that there could be no type and that if someone should bring to light a specimen in, say, Philadelphia, bearing the notation "this is the specimen seen in the United States by Bonaparte" it would immediately become as important as the one in London. Any American weasel or weasels (then alive or preserved in a zoölogical collection) that Bonaparte saw in the United States probably were of the eastern United States. Bangs (1896:18-21), for one, previous to the present consideration of the name cicognanii, restricted it to the ermine of the eastern United States. Consequently, the name cicognanii, in the present account is applied to the ermine of the eastern United States. In my opinion there was and is no type. Almost certainly there was no type if the Fauna Italica appeared before the account in Charlesworth's Magazine did.

Specimens examined.—Total number, 172, arranged alphabetically by provinces and states, then (except where indication is given to the contrary) by counties from north to south within each state or province. Unless otherwise indicated, specimens are in the U. S. National Museum.

Connecticut. Windham County: S. Woodstock, Woodstock Lake, 1. Hartford County: Windsor, 1. New London County: Liberty Hill, 3.

Maine. Aroostook County: Quimby, 1; Ashland 2. Piscataquis County: tableland on top of Mt. Katahdin, 1; Chimney Pond, 3; T. 5, R. 13, 3; "vicinity of Chesnucook," 1; T. 4, R. 13, 1; Moosehead Lake, 7; Grenville, 10 ; Barnard, 3 (1). Penobscot County: South Twin Lake, 1; Lincoln, 11 (7, 2, 2). Franklin County: Seven Pond Township, 7. Oxford County: Umbago Lake, 1; Upton, 4; Bethel, 1. Hancock County: Bucksport, 17; Naskeag, 1. Lincoln County: Booth Bay, 1.

Massachusetts. Middlesex County: Wilmington, 2; Burlington, 6 (1); Worcester County: Cambridge, 5 (1, 3); Sterling, 1. Plymouth County: Middleboro, 7 (1).

New Hampshire. Carroll County: Ossipee, 5. Rockingham County: Greenland, 1. Cheshire County: Dublin, 1.

New York. St. Lawrence County: Ogdensburg, 1. Franklin County: Malone, 1. Lewis County: Locust Grove, 1. Warren County: Lake George, 1. Montgomery County: Amsterdam, 1. Albany County: Albany, 1. Rensselaer County: Berlin, 2; Schoharie, 1. Thompkins County: Cascadilla Creek, Ithaca, 1. Allegany County: Ford Brook, Wellsville, 1. Ontario County: Phelps, 1. Cattaraugus County: Cattaraugus, 1.

Ontario (localities locally north to south, then west to east). Thunder Bay Dist.: Grand Bay, Lake Nipigon, 5; Macdiarmid, 2; Oscar, 2; 20 mi. SW Fort Williams, 1; Michipicoten Island, 3. Algoma Dist.: Michipicoten, 1; Franz, 1; Pancake Bay, 2. Parry Sound Dist.: French River, Georgia Bay, 1; Seguin Falls, Twp. Montieth, 1. Sudbury Dist.: Casselman, Rathbun Twp., 1. Nipissing Dist.: Smoky Falls, near Kapuskasing, 4; Franks Bay, Lake Nipissing, 1. Haliburton County: Gooderham, 1. Simcoe County: Orillia, 1; no locality more definite than county, 1. Carleton County: Britannia, 5 mi. W Ottawa, 1; Ottawa, 1; Constant Bay, NE? of Ottawa, 1. Wellington County: Mt. Forest, 2; Guelph, 1. Addington County: Buckshot Lake, Abinger Twp., 1. Fontenac County: Clear Lake, Arden, 1.

Pennsylvania (by counties from west to east). Crawford County: North Shenango Township, Pymatuning Swamp, 2; Linesville (3 mi. NW, 1; 3-1/2 mi. W, 2; 3 mi. W, 1; 2 mi. SW, 1; 7-1/2 mi. SW, 1) 6. Potter County: Cherry Springs Farm, Abbott Township, 1; 3 mi. S Inez, South Fork Sinnamahoning Creek, 1. Sullivan County: Lopez, 1. Lackawanna County: Scranton, 1. Wayne County: Waymart, 1.

Quebec (west to east). Labelle County: Kamika [= Kiamika] Lake, 2; Lacoste, 2; Trout Lake, probably in this county, 2. Megantic County: Black Lake, 1.

Rhode Island. Newport County: Middletown, 2.

Vermont. Lamoille County: Mt. Mansfield, 1. Windsor County: Barnard, 1.

Mustela erminea bangsi Hall

Ermine

Plates , , , , and

Mustela erminea bangsi Hall, Journ. Mamm., 26:176, July 19, 1945.

[Putorius] cicognani, Mearns, Bull. Amer. Mus. Nat. Hist., 3:235, June 5, 1891.

Putorius richardsoni cicognani, Bangs, Proc. Biol. Soc. Washington, 10:18, February 25, 1896 (part).

Putorius cicognanii, Cory, Mamm. Illinois and Wisconsin, p. 375, 1912.

Mustela cicognanii, Aldous and Manweiler, Journ. Mamm., 23:250, August 13, 1942.

Mustela cicognanii cicognanii, Bailey, N. Amer. Fauna, 49:169, January 8, 1927; Leraas, Journ. Mamm., 23:344, August 13, 1942.

Type.—Male, subadult, skull and skin; no. 11541, D. R. Dickey Coll.; Elk River, Sherburne County, Minnesota; November 1, 1925; obtained by Bernard Bailey, original no. A 606.

The skull is complete and the teeth all are present and entire. The skin is well made and in a good state of preservation.

Range.—Southern Manitoba, northeastern North Dakota, the whole of Minnesota, Wisconsin and Michigan and northern Iowa. See figure 25 on page .

Characters for ready recognition.—Differs from M. e. richardsonii, in that, in both sexes, least width of color of underparts averages about a third, instead of two-fifths, of greatest width of color of upper parts, and in that skulls of males are a fifth or more lighter, basilar length averaging less than 40; from M. e. cicognanii, in that hind foot more than 40 in males, averaging 32 versus 30 in females, and in larger skull, depth of skull at plane of molars being 11.4 versus 10.0 in males and 9.1 versus 8.6 in females.

Description.—Size.—Male: Twelve adult and subadult males from Aitkin, Minnesota, yield average and extreme measurements as follows: Total length, 316 (291-341); length of tail, 87 (70-101); length of hind foot, 43 (40-44). Two adults from Aitkin each weigh 170 grams.

Four adult and subadult females from Elk River and Fort Snelling, Minnesota, yield average and extreme measurements as follows: Total length, 249 (240-260); length of tail, 61 (55-65); length of hind foot, 32 (30-33).

Color.—As described in Mustela erminea richardsonii except that, least width of color of underparts averaging, in males from Minnesota, 32 (19-51) per cent of greatest width of color of upper parts. Black tip of tail in 12 male topotypes in white winter pelage averaging 52 (45-58) mm. which is 60 (53-66) per cent of length of tail-vertebrae.

Skull.—Male (based on adults from Aitkin): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight of 2 adults from Aitkin, 2.2, 2.3 grams (9 subadults from T. 61 N, R. 26 W, average 1.95 grams); basilar length, 39.7 (38.5-40.7); length of tooth-rows rarely more (usually less) than length of tympanic bulla.

Female (based on adults from Minnesota as listed in table of cranial measurements, which see): See plates -. As described in Mustela erminea richardsonii except that: Weight, of a subadult from T. 61 N, R. 26 W, 0.91 grams; basilar length, 32.8 (31.8-33.6); breadth of rostrum rarely equal to as much as 30 per cent of basilar length.

From richardsonii, topotypes of bangsi differ in that cranial measurements in males are approximately 7 (5-9) per cent less, linear measurements of teeth are 10 (9-11) per cent less and the skull is a fifth lighter. In relation to basilar length the tympanic bullae of bangsi are longer. Skulls of females are individually indistinguishable, those of bangsi averaging approximately 1 per cent less in linear measurements. Comparison with the smaller cicognanii is made in the account of that subspecies.

Remarks.—Before the subspecific name bangsi was proposed, individuals of this subspecies ordinarily were recorded in the literature as Mustela cicognanii. The best single lot of material is in the zoölogical collection of the University of Wisconsin. The late naturalist Albert Lano preserved a large share of the material from Minnesota. The large series from Elk River of that same state was mostly collected by Bernard Bailey although his Aunt, Anna (Bailey) Mills, and her brother the late Vernon Bailey, at an earlier time saved some specimens from Elk River. The name bangsi was proposed in recognition of the superior work done on American weasels by the late Outram Bangs.

From the range of M. e. invicta in the Rocky Mountains, that of bangsi is separated by the Great Plains from a large part of which region the species is unknown. M. e. bangsi differs from invicta in greater degree of sexual dimorphism in size, and in each sex by larger size, narrower light-colored underparts, and deeper braincase as measured at the anterior margin of the basioccipital. In bangsi the braincase is deeper relative to the length of the skull as well as, of course, actually deeper.

Of the two subspecies whose ranges do meet that of bangsi, it more closely resembles richardsonii than cicognanii. From richardsonii, especially from southeastern populations of the same in which the skull is of the same size as in bangsi, the latter differs in longer hind feet. This is an average difference and by one interpretation the animals here referred to bangsi might be lumped with some of the populations from the southeastern part of the range of richardsonii and the whole lot treated as intergrades between richardsonii and cicognanii. Nevertheless, the animals here referred to bangsi are not geographically intermediate between richardsonii and cicognanii and this consideration had much to do with the decision to recognize as a separate subspecies the animals here named bangsi.

Within the range of the subspecies there is some geographic variation; the hind feet of animals from Iowa average slightly shorter than those of animals from Minnesota and Wisconsin but are nowhere nearly so short as in cicognanii at the same latitude in the eastern United States.

It is noteworthy that the few specimens seen from Isle Royal have the long hind feet of bangsi and not the short hind feet of cicognanii which occurs all along the northern mainland.

Because an oft cited record of occurrence even though erroneous, has a way of being repeated in later works, attention is here called to the alleged occurrence of this ermine in northwestern Ohio at New Bremen. Henninger (1921:239) published the original account of the supposed occurrence but as I pointed out in 1937 (p. 304), the specimen concerned proved upon examination to be a female of Mustela frenata noveboracensis. Henninger was misled probably by the short tail; the end of the tail had been lost and healed over before the animal's death. The present study has revealed that M. erminea everywhere east of the Cascade Mountains assumes a white winter coat. Had this been known when Henninger obtained his specimen he probably would not have wrongly identified the animal from New Bremen which was in the brown, winter pelage.

Specimens examined.—Total number, 222, arranged alphabetically by provinces and states and, arranged from north to south, by counties in each state. Unless otherwise indicated, specimens are in the University of Wisconsin Museum of Zoölogy.

Iowa. Dickinson County: W side Lake Okobogie, 1. Winnebago County: Lake Mills, 7. Worth County: Northwood, 1. Clay County: "Dewey's Pasture, near Ruthven," 1.

Manitoba. Aweme, 4; Red River Settlement, 1.

Michigan. Isle Royal: Tobin Harbor, 1; Bell Isle, 1; Washington Harbor, 3. Ontonagon County: Ontonagon, 2 (1, 1); T. 51N, R. 43W, S. 17, Porcupine Mts., 1. Gogebic County: Little Girls Point, 5; Ironwood, 1. Iron County: no locality more definite than county, 1. Luce County: Tahquamenon River Falls, 1. Chippewa County: Sault Ste. Marie, 2. Emmet County: Wilderness State Park, 2. Cheboygan County: Univ. Mich. Biol. Station, 1. Washtenaw County: Ann Arbor, 1.

Minnesota. Kittson County: no locality more definite than county, 1. Roseau County: Deer Township, 1; Falun Township, 2. Marshall County?: Moose River, 5; Warren, definitely in Marshall County, 1. Cook County: Grand Marais, 3 (2, 1). St. Louis County: 2 mi. E Babbitt, 14; Burntside [= Burnside] Lake, 1. Itasca County: T. 61N, R. 26W, 23. Clay County: Moorhead, 3. Aitkin County: Aitkin, 13 (11, 1, 1). Otter Tail County: Arthur, 3; Ten Mile Lake, 1; Parkers Prairie, 2. Chisago County: North Branch, 1. Sherburne County: Elk River, 42 (16, 5, 20, 1). Hennepin County: Lake Minnetonka, 1; Minneapolis, 1; Fort Snelling, 5 (4, 1).

North Dakota. Pembina County: Walhalla, 1. Nelson County: Stump Lake, 1. Eddy County: Brantford, 2.

Wisconsin. Douglas County: T. 44N, R. 13W, 1; Gordon, 1. Bayfield County: Brinks Camp, Washburn, 1; "near Cable," 1. Ashland County: Bear Lake, 2. Iron County: Fisher Lake, 4; Mercer, 5. Vilas County: Mamie Lake, 16; Ox Bow Lake, 1. Oneida County: Tomahawk Lake, 1. Langlade County: T. 34N, R. 11E, 3. Rush County: Ladysmith, 1. Dunn County: Colfax, 2. Door County: Mink River, Ellison Bay, 1. Dodge County: Fox Lake, 1; Beaver Dam, 12.

Mustela erminea invicta Hall

Ermine

Plates , , , , , and

Mustela erminea invicta Hall, Journ. Mamm., 26:75, February 27, 1945; Hall, Journ. Mamm., 26:180, July 19, 1945.

Putorius cicognanii, Preble, N. Amer. Fauna, 27:230, October 26, 1908.

Type.—Male, subadult, skull and skin; no. 101122, Mus. Vert. Zoöl.; Benewah, Benewah County, Idaho; October 24, 1926; obtained by William T. Shaw.

The skull has a hole in the right squamosal bone on the floor of the braincase, and lacks the hamular process of the left pterygoid. The postmolar part of the right lower jaw is missing. The teeth all are present and entire. The skin is in white, winter pelage, well made, and in a good state of preservation.

Range.—Central Rocky Mountain region from Jasper Park south over Alberta, southeastern British Columbia, Washington east of the Cascades, and north and central Idaho and northwestern Montana. See figure on page .

Characters for ready recognition.—Differs from M. e. richardsonii, in males, by skull lighter than 1.9 grams, mastoid breadth less than 19.9, depth of skull at anterior margin of basioccipital less than 12.4, in females by corresponding measurement of depth less than 10.1, and weight of skull less than one gram; from M. e. fallenda, in both sexes, by upper lips white (not brown), in males by skull averaging longer (37.0 versus 35.7), in females by breadth of rostrum less, instead of more, than 30 per cent of basilar length; from M. e. streatori, gulosa, and muricus by hind foot more than 36 and basilar length more than 35 in males and by hind foot more than 29.5 and basilar length more than 30.5 in females; further distinguished from streatori by white (not brown) upper lips and from gulosa by black tip of tail more than half length of tail-vertebrae.

Description.—Size.—Male: Ten adults and subadults from central Idaho County yield average and extreme measurements as follows: Total length, 291 (272-328); length of tail, 86 (75-100); length of hind foot, 39.9 (38-44).

Female: Five adults and subadults from the same locality yield average and extreme measurements as follows: Total length, 255 (245-270); length of tail, 71 (68-76); length of hind foot, 32.3 (32-33).

Color.—As described in Mustela erminea richardsonii except that underparts in summer Marguerite Yellow or more whitish; least width of color of underparts averaging, in four females from Idaho and Montana, 38 (33-43) per cent of greatest width of color of upper parts. Black tip of tail in same specimens 38 (31-42) mm. which is 57 (52-65) per cent of length of tail-vertebrae.

Skull.—Male (5 adults from Idaho County): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.5 (1.4-1.7) grams; basilar length, 37.0 (35.8-39.8).

Female (illustrated by adult and 4 subadults in table of cranial measurements, which see): See plates -. As described in Mustela erminea richardsonii except that: Weight, 0.72 (0.7-0.9) grams; basilar length, 32.2 (31.6-32.8).

From fallenda, invicta differs in that the skull of the male has a relatively narrower rostrum and relatively shallower braincase. Females show the same differences but the degree of difference is about as great again as in males. The teeth are almost exactly the same size in the two subspecies. The weight is the same in males but in females invicta is 18 per cent heavier.

From streatori, invicta differs in that males average larger in every measurement taken except that the anteroposterior diameter of the inner moiety of M1 is less; 36 per cent heavier; linear measurements of the skull are about 5 per cent larger and those of the teeth, with the one exception noted, about 6 per cent larger; relative to the basilar length the tympanic bullae are longer and the rostrum is relatively narrower. In females, measurements of the skull average 8 per cent more and those of the teeth 7 per cent more except that, as in males, the inner lobe of M1 is actually shorter. Females of invicta are 12 per cent heavier; relative to the basilar length the skull is narrower throughout and the tooth-rows are shorter than in streatori.

From gulosa, invicta differs in that males average larger (about 12 per cent) in every measurement taken, excepting the anteroposterior diameter of M1 which is the same; 50 per cent heavier; relative to the basilar length the length of the tooth-rows and interorbital breadth are less. In females the inner lobe of M1 is smaller but every other measurement taken of the skull and teeth is more, invicta averaging about 8 per cent larger and 22 per cent heavier; relative to the basilar length, the tooth-rows are shorter and the skull is narrower interorbitally, through the rostrum and across the zygomata.

From murica, invicta of corresponding sex differs in being larger in every measurement taken; males average 17 per cent larger in cranial measurements, 13 per cent larger in dental measurements and are 83 per cent heavier; corresponding percentages for females are 11, 9 and 20. Exception must again be made for the anteroposterior diameter of the inner lobe of the last upper molar which is less in females, and only slightly more in males. In males of invicta the tympanic bullae are longer in relation to the basilar length.

From the geographically remote cicognanii, skulls of both males and females of invicta are to me individually indistinguishable. There is, nevertheless, an average difference not apparent to the eye between skulls of males. If the length of the tooth-rows be taken as a standard (100 per cent), the rostrum, of invicta, as measured across the lacrimal processes is broader (89 rather than 84 per cent) but the width across the fourth upper premolars is less, 94 rather than 97 per cent of the length of the tooth-rows.

Since the skull of invicta closely resembles that of cicognanii, it follows that invicta differs from richardsonii and bangsi in about the manner described in the account of cicognanii.

Remarks.—Animals of this subspecies in advance of the present study generally were recorded in the literature under the name Mustela cicognanii. The difficulty in distinguishing individual specimens of invicta on morphological grounds from those of the geographically remote M. e. cicognanii should not be taken to indicate that the populations do not differ appreciably. Actually they differ in several characters although in no one of these is the degree of difference sufficient to allow of using it alone as a certain means of diagnosis. In invicta, as compared with cicognanii, the light-colored underparts are wider in relation to the dark-colored upper parts and the tail is longer by 4 per cent relative to the head and body. Given a population of each of the two subspecies, in which the skull is of the same mass, the hind feet are longer in invicta, there is more sexual dimorphism in size, and the anterior part of the skull differs in some particulars as just described in the comparison of the skull of invicta with other forms. Nevertheless, each of these differences is of an average sort. Therefore, and because overall size is about the same in the two subspecies concerned, one or a few specimens from, say, central Idaho, can be distinguished from animals from western Pennsylvania only with difficulty, if at all. The close resemblance of skulls of invicta and cicognanii may be a function of their living at approximately the same latitudinal position in a climate that has marked seasonal variation.

Intergradation with richardsonii is complete and gradual; in one sense invicta is but little more than a small richardsonii. Intergradation with fallenda is shown by several specimens. These two races differ in large degree in color, and in size and shape of the skull of females. Although the geographic area where intergradation in color occurs is fairly wide, the area in which intergradation in cranial characters in females occurs, appears, from the inadequate material available, to be much narrower. Intergradation occurs freely in Washington with streatori but with muricus so far as known only in the Bitterroot and nearby mountains of northwestern Montana. The Snake River Plains and low country along much of the Columbia River appears to be uninhabited by weasels of the species erminea and hence there is opportunity for intergradation only in the mentioned area of Montana.

Specimens examined.—Total number, 177, as follows. Arranged alphabetically by provinces and states then by localities from north to south in each province and by counties from north to south in each state. Unless otherwise indicated, specimens are in the United States National Museum.

Alberta. Jasper House, 4; Shovel Pass, 2; Jasper Park, 10; head of Smoky River, 9; Henry House, 2 (1); Blindman River, 1; forks of Blindman River and Red Deer River, 2 (1, 1); "near Red Deer, Red Deer River," 1; Red Deer River, 2 (1, 1); Red Deer, 2; Rosebud, 2; Prairie, 3000 ft., 1; Didsbury, Little Red Deer River, 1; Canadian Nat'l Park, 1; Canmore, 1; Banff, 1; High River, 1; "Waterton Lake Park" in Alberta, 6.

British Columbia. Grand Forks of Fraser River, 1; Canoe River, 1; Field, 1; Glacier, 1; E side Beaverfoot Range, 4000-4500 ft., 6 mi. SE Fraser Creek, 8; Wentworth Lake, 1; Revelstoke, 2 (1, 1); Spillimacheen[e]en River, 2; Sicamous, 2; Albert River, 7000 ft., 1; Lumby, Creighton Valley, 1; Okanagan, 4 (2, 1, 1); Kettle River Lake, Gold Range, 4000 ft., 1; Crows Nest Station, 1; Yale District, 3; Fort Hope, 1; Chilliwack Lake, 1; Skagit, 2 (1, 1); Skagit Valley, 1; Skagit Summit, 1; Lightning Lakes, 2 mi. N International Boundary, 3; Osoyoos-Bridesville Summit, 2; Westbridge, 1; Rossland, 5; Creston, mouth Goat Creek, 3; Yahk, 4.

Idaho. Bonner County: Coolin, 4. Benewah County: Benewah, 1. Idaho County: "Pete Kings, Lochsa River," 1; 2 mi. SSE Selway Falls, 1900 ft., 1; 4 mi. SW Selway Falls, 5800 ft., 3; Newsome Cr., 12 mi. above jct. with S Fk. Clearwater River, 2; Iron Mt., to 14 mi. W thereof, 24; Pilot Cr., 3/4 to 2-1/2 mi. above Newsome Cr., 4; Sawmill Cr., 1-1/4 mi. W Newsome, 1; between Selway River and S. Fk. Clearwater R., 4.

Montana. Teton County (of old arrangement of counties): Many Glacier, 4900 ft., 1; Duck Lake, 6 mi. NE St. Marys Lake, 1; St. Marys, Glacier Park, 1; Lower St. Marys Lake, 1. Flathead County: Stanton Lake, 5. County in question: Bitter Root Mts., 1. Ravalli County: Tin Cup District, 1; Bass Creek, 6800 ft., NW of Stevensville, 1; Capitan Peak, 7000 ft., 1; Darby, 2; Girds Creek, 1; Charlos Heights, 2.

Washington. Whatcom County: Twin Lakes, Winchester Mts., 3 (1); Chilliwack River, 2600 ft., 2; Cooper Creek, near head, 4500 ft., Hannegan Pass, 1; Cooper Cr., 4300 ft., Hannegan Pass, 1; Beaver Creek (2500 ft., and at McMillan Ranch, 1700 ft.), 2; Barron, Bornite Mine, 5000 ft., 1. Okanogan County: Tungsten Mine, 6800 ft., Bauerman Ridge, 4; Hidden Lakes, 4100 ft., 1; West Fork Pasayten River, 4700 ft., 1. Stevens County: Orin, 1. Pend Oreille County: Ione, 2. Chelan County: Lake Chelan, 1.

Mustela erminea alascensis (Merriam)

Ermine

Plates , , , , and

Putorius richardsoni alascensis Merriam, N. Amer. Fauna, 11:12, pl. 2, figs. 2, 2a, June 30, 1896.

Putorius cicognanii alascensis, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Swarth, Univ. California Publ. Zoöl., 7:140, January 12, 1911.

Mustela erminea alascensis, Hall, Proc. Biol. Soc. Washington, 57:36, June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.

Type.—Male, adult, skull and skin; no. 74423, U. S. Nat. Mus., Biol. Surv. Coll.; Juneau, Alaska; August 22, 1895; obtained by Clark P. Streator, original no. 4806.

The skull shows malformation of the frontal sinuses due to parasites and lacks osseous tissue where the parasitic infestation was localized. The left exoccipital condyle and adjacent region is less developed than the right and the posterior part of the skull is bent slightly to the left. Otherwise the skull is unbroken. The teeth all are present and entire. The skin is in the brown summer coat, fairly well made and in a good state of preservation. A few white hairs persist where the proximal line of the black hair of the tip of the tail meets the distal line of the brown hair.

Range.—Mainland of southeastern Alaska from Lynn Canal south to include Mitkof, Zarembo, Wrangel and Revillagigedo islands. See figures , on pages 95 and 134.

Characters for ready recognition.—Differs from M. e. arctica and haidarum, in both sexes, by proximal two-thirds of under side of tail colored same as upper parts rather than same as underparts and interorbital breadth less, instead of more, than distance between glenoid fossa and posterior border of external auditory meatus; from M. e. salva, in males, by overall depth of braincase including tympanic bullae less than 89 per cent of orbitonasal length, females not individually distinguishable but averaging shallower through the braincase; from M. e. initis, celenda and seclusa by interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus (females of initis, celenda and seclusa unknown); further from initis by total length less than 317 and black tip of tail less than 57 per cent of length of tail-vertebrae; further from celenda by chest white, not mostly covered by brown patch.

Description.—Size.—Male: Eight adults from Windham, Alaska, yield average and extreme measurements as follows: Total length, 298 (288-315); length of tail, 88 (84-94); length of hind foot, 41.3 (37-44).

Female: Two adults from Juneau and Helm Bay measure, respectively, as follows: Total length, 258, 258; length of tail,——, 76; length of hind foot, 32, 34.

Color.—As described in Mustela erminea richardsonii except that least width of color of underparts averaging, in five females, 42 (35-53) per cent of greatest width of color of upper parts. Black tip of tail in same specimens averaging 36 (30-40) mm. which is 49 (48-53) per cent of length of tail-vertebrae.

Skull.—Male (based on 8 adults from Windham): See measurements and plates, 2-4. As described in Mustela erminea richardsonii except that: Weight, 1.8 (1.5-2.6) grams; basilar length, 37.5 (36.5-38.9); length of tooth-rows more or less than (about same as) length of tympanic bulla.

Female (based on 5 adults, from localities listed in the table of cranial measurements): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 0.96 (0.7-1.1) grams; basilar length, 32.7 (31.9-33.2); breadth of rostrum more or less than (about equal to) 30 per cent of basilar length.

From richardsonii, alascensis differs in that the skull of the male averages smaller in every measurement taken and is 28 per cent lighter. Relative to the basilar length, the orbitonasal length is more and the braincase is shallower as measured at the anterior end of the basioccipital. The four adult females seen of alascensis are more variable than those of richardsonii and average smaller in some measurements and larger in others but give no proof of any consistent difference.

From haidarum, alascensis differs in that the rostrum and entire preorbital part of the skull is actually as well as relatively much smaller in both sexes. In males of alascensis the length of the skull, and other cranial measurements of length, is more. In males, the mastoid breadth and zygomatic breadth are about the same as in haidarum, as also is the weight. M1 is larger but m1 and P4 are smaller. In females the anteroposterior extent of the inner moiety of M1 and length of tympanic bulla are about the same in the two subspecies but all other cranial and dental measurements in alascensis are less. It is 29 per cent lighter. The difference in the preorbital region is of about the same degree as in the males.

Comparisons of the skull with those of arctica, salva, initis, celenda, and seclusa are made in the accounts of those subspecies.

Remarks.—The relatively few specimens known of this race seem always to have been referred to in the literature by the name alascensis and the nomenclatural history is therefore simple. The original materials were obtained by the collector Clark P. Streator and the additional series of skeletons, one with skin, from Windham were procured by Stanton Price, a resident there.

The subspecies is well differentiated from both arctica and richardsonii. Although actual intergrades are lacking between alascensis and the two races just mentioned I have no doubt that intergradation occurs with richardsonii and think it probably does also with arctica.

The assignment of the three females from Mitkof Island, Zarembo Island, and Loring on Revillagigedo Island, is tentative because each is so young as not to show diagnostic cranial characters. The two other specimens from Revillagigedo Island (Carroll Inlet), labeled as males, are in white winter pelage. Only one, no. 136358, a subadult, is accompanied by a skull. The small size of each specimen, and its cranial characters which are intermediate between those of males and females of alascensis of the adjacent mainland, indicate the existence of a distinct race of weasel on Revillagigedo Island. On the chance that the one specimen with a skull is a dwarf, or is wrongly sexed as seems improbable, the population is tentatively referred to alascensis.

Specimens examined.—Total number, 24, arranged by localities from north to south. Unless otherwise indicated, specimens are in the Museum of Vertebrate Zoölogy, University of California.

Alaska. Juneau, 5; Taku River, 1; Windham, 9; Mitkof Island, 1; St. John Harbor, Zarembo Island, 1; Wrangel, 1; Helm Bay, Cleveland Peninsula, 1; Cleveland Peninsula, 2; Revillagigedo Island, Carroll Inlet, 2; Loring, 1.

Mustela erminea salva Hall

Ermine

Plates , , , , and

Mustela erminea salva Hall, Proc. Biol. Soc. Washington, 57:35, June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.

Type.—Male, adult, skull only; no. 74641, Mus. Vert. Zoöl.; Mole Harbor, Admiralty Island, Alaska, December 27, 1936; obtained by A. Hasselborg.

The skull (plates -) shows malformation of the frontal sinuses owing to parasites and lacks osseous tissue where the parasitic infestation was localized. The skull is unbroken. The teeth all are present and entire.

Range.—Admiralty Island, Alaska. See figures , on pages , .

Characters for ready recognition (known only from skulls).—Differs from males of M. e. alascensis in overall depth of braincase which is more than 89 per cent of orbitonasal length; from M. e. initis, in males, in that orbitonasal length and mastoid breadth total less than 35 mm., weight of skull and lower jaws less than 2.1 grams; from M. e. celenda, in males, in that breadth of rostrum measured across lacrimal processes less than a third of basilar length.

Description.—Size.—Male: An adult from Gambier Bay measures: Total length, 320; length of tail, 95; length of hind foot, 45 (41 in dry skin).

Female: A subadult from Hawk Inlet, measures: Total length, 250; length of tail, 70; length of hind foot, 33.

Color.—As described in Mustela erminea richardsonii except that least width of color of underparts in four individuals 40 (38-43) per cent of greatest width of color of upper parts. Black tip of tail, in two individuals for which external measurements are given, amounting to 50 and 40 mm. respectively which is 53 and 57 per cent of length of tail-vertebrae.

Skull.—Male (type and 4 adult topotypes): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.7 (1.5-1.9) grams; basilar length, 37.8 (36.4-39.5, extremes are in subadults); length of tooth-rows more or less (usually more) than length of tympanic bulla; interorbital breadth rarely more than distance between glenoid fossa and posterior border of external auditory meatus.

Female (2 ad. and 1 ad.-sad. topotypes): See measurements, and plates -. As described in Mustela erminea richardsonii except that: Weight, 0.9 (0.8-1.0) grams; basilar length, 33.0 (32.0-33.6); length of tooth rows approximately same as length of tympanic bulla; breadth of rostrum approximately 30 per cent of basilar length.

From alascensis, salva differs in that males have the preorbital region slightly wider in relation to the length of the tympanic bulla; also the braincase is smaller, actually as well as in comparison with the preorbital part of the skull. The tympanic bullae do not project so far below the squamosals and the braincase itself is shallower, in adults averaging only 11.5 mm. as against 12.5 mm. The overall depth of the braincase, including the tympanic bullae, when divided into the orbitonasal length gives an average of 93 (90-97) per cent whereas in alascensis the figure is only 85 (78-88) per cent. On this basis alone, everyone of the adult skulls of the two races can be distinguished. The females and subadult males show the same tendency to reduction in depth of braincase but not every individual among them can be surely distinguished. By weight the skull of salva of corresponding sex is only about 6 per cent smaller. Comparisons with initis and celenda are made in the accounts of those subspecies.

Remarks.—Most of the specimens seen were collected by Allen E. Hasselborg, resident on Admiralty Island. On the basis of skulls—few skins, and measurements taken in the flesh, are available—salva more closely resembles alascensis than does any other subspecies so far known from southeastern Alaska. The race on Admiralty Island is only slightly differentiated from alascensis of the adjacent mainland.

Specimens examined.—Total number, 26, all from Admiralty Island, Alaska, arranged in general by localities from north to south, and unless otherwise indicated in the Museum of Vertebrate Zoölogy, University of California.

Alaska. Admiralty Island: Hawk Inlet, 2; Seymour Canal, 4; Mole Harbor, 18 (skulls only); Gambier Bay, 1; no locality more definite than Admiralty Island, 4 (1 in U. S. Nat. Mus.).

Mustela erminea initis Hall

Ermine

Plates , and

Mustela erminea initis Hall, Proc. Biol. Soc. Washington, 57:37, June 28, 1944; Hall, Journ. Mamm., 26:180, July 19, 1945.

Type.—Male, adult, skull and skin; no. 289, Mus. Vert. Zoöl.; Saook Bay, Baranof Island, Alaska; October 9, 1907; obtained by A. Hasselborg, original no. 4.

The top of the skull is fractured on the left side from the anterior nares posteriorly through the postorbital process to the posterior root of the zygomatic arch. On the left lower jaw the canine and three incisors are missing; otherwise the teeth all are present and entire.

The skin is in process of molt, approximately nine-tenths of the incoming white pelage being in place. The skin is well made and in a good state of preservation.

Range.—Chichagof and Baranof islands, Alaska. See figures , on pages 95, 134.

Characters for ready recognition (only males known).—Differs from M. e. arctica, in that proximal two-thirds of under side of tail colored same as upper parts rather than same as underparts, zygomatic breadth less than distance between last upper molar and jugular foramen; from M. e. salva in that orbitonasal length and mastoid breadth total more than 35 mm., weight of skull and lower jaws more than 2.1 grams; from M. e. alascensis, by total length more than 317, black tip of tail more than 57 per cent of length of tail-vertebrae, interorbital breadth more than 10.3 and equal to, instead of less than, distance between glenoid fossa and posterior border of external auditory meatus; from M. e. celenda by chest white (not mostly covered by brown patch), breadth of rostrum measured across lacrimal processes less than a third of basilar length; from M. e. seclusa in zygomatic breadth more than distance between last upper molar and jugular foramen.

Description.—Size.—Male: The type and an adult topotype measure, respectively, as follows: Total length, 330, 320; length of tail, 95, 95; length of hind foot, 45, 45.

Female: No external measurements available.

Color.—As described in Mustela erminea richardsonii except that least width of color of underparts averages, in two young female topotypes, 50 (49, 50) per cent of greatest width of color of upper parts. Black tip of tail in three young female topotypes averaging 54 (52-55) mm. which is 67 (63-69) per cent of length of tail-vertebrae.

Skull.—Male (illustrated by type and 1 ad. topotype): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 2.3 and 2.5 grams; basilar length, 39.6, and 40.5; interorbital breadth equal to distance between glenoid fossa and posterior border of external auditory meatus.

Female: No adults available.

From salva, initis differs in that skulls of males average larger in every measurement taken, being 41 per cent heavier. Relative to the basilar length, the interorbital and preorbital parts of the skull are larger; the relatively greater interorbital and mastoid breadths are particularly noticeable. Although the depth of the braincase, including the tympanic bullae, is both relatively as well as actually more than in salva, the depth is relatively less than in alascensis which otherwise differs from initis in about the same way that salva differs from initis. Whereas the interorbital breadth in initis is about equal to the distance between the glenoid fossa and the posterior border of the external auditory meatus, the interorbital breadth is uniformly less than this distance in both salva and alascensis. In comparison with seclusa the teeth are of the same size but all measurements of the skull are larger. The skull of initis is 25 per cent heavier. In relation to the basilar length, the interorbital and preorbital parts of the skull are much less in initis. The preorbital and interorbital regions in initis are relatively smaller in comparison also with arctica. The one measurement of interorbital breadth in initis is greater in relation to the basilar length than in kadiacensis but the rostral region, and all that part of the skull anterior to the braincase, is relatively smaller in initis.

Remarks.—The two adult males, nos. 286 and 289 from Saook Bay, provide convincing evidence of the existence of a distinct race of weasel on Baranof Island. Three other young specimens, almost subadult, from the same place are labeled as males although the basilar lengths of these skulls are only 35.5, 35.9 and 37.3 millimeters as against 39.6 and 40.5 in the two adult males. The difference in size is too great to be age-variation. The fact that 3 are definitely of one category and 2 of the other makes it doubtful that individual variation accounts for the differences. The small size of these 3 specimens and the fact that in each the anterior margin of the tympanic bulla is flush with the squamosal rather than protruded from the braincase, suggests that the three are females. If they are females, the amount of secondary sexual variation is rather less than would be expected by analogy with the amount obtaining in alascensis on the mainland and in salva on Admiralty Island. Another possibility that I can not disprove is that two stocks of weasels persist on Baranof Island, the two larger specimens being descendants of the stock which first became established on the island and the three smaller specimens being descendants of an individual ermine, or of ermines, that were rafted or otherwise transported to the island at a considerably later date. Assuming for the moment that there are two stocks, it must be admitted that each one differs from any stock known from elsewhere. Therefore, each stock would be presumed to have been long resident on the island. But—two stocks as closely related as the two in question would not be expected to persist for long in an area as small as that of Baranof Island because competition would give one the ascendancy. Therefore, the first suggestion, namely that the three smaller animals are really females, seems the more probable. The feasible way to clear up the present uncertainty is, of course, to obtain additional specimens, carefully labeled as to sex. Yet another reason why additional collecting is desirable in this area is to ascertain whether there is subspecific differentiation between the ermines of Baranof and Chichagof islands. The one specimen available from the latter island, although in general like the three smaller animals from Baranof Island, differs in the fuller (less scooped out) medial side of the tympanic bulla and to a slight degree in each of some other features. This specimen from Chichagof Island is labeled as a male also.

Specimens examined.—Total number, 6, arranged by localities from north to south, and in the Museum of Vertebrate Zoölogy, University of California.

Alaska. Chichagof Island, Freshwater Bay, 1. Baranof Island, Saook Bay, 5.

Mustela erminea celenda Hall

Ermine

Plates , and

Mustela erminea celenda Hall, Proc. Biol. Soc. Washington, 57:38, June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.

Type.—Male, adult, skull and skin; no. 130987, U. S. Nat. Mus., Biol. Surv. Coll.; Kasaan Bay, Prince of Wales Island, Alaska; June 16, 1903; obtained by Cyrus Catt; original no. 4407X.

The skull has a piece 1.5 mm. long broken out of the left zygomatic arch. P2 is absent on both sides. The right I1, and the left I1 and I2 are missing. The skin, in summer pelage, is fairly well made. A scrotal pouch attests to the correctness of the sex recorded on the label. The rostral part of the skull is smaller than in average-sized males of corresponding age.

Range.—Prince of Wales, Dall, and Long islands, Alaska. See figures , on pages , .

Characters for ready recognition (only males known).—Differs from M. e. alascensis and initis in chest mostly covered by brown patch, not white, and breadth of rostrum measured across lacrimal processes more than a third of basilar length, which cranial character serves to distinguish also salva; from M. e. seclusa in zygomatic breadth less than distance between last upper molar and jugular foramen; from M. e. haidarum in chest white (not mostly covered by brown patch), proximal two-thirds of underside of tail colored like upper parts rather than underparts, basilar length more than 38.2 mm.

Description.—Size.—Male: Seven adults and subadults from Prince of Wales Island, yield average and extreme measurements as follows: Total length, 286 (277-304); length of tail, 77 (74-85); length of hind foot, 36 (35.5-40.5).

Female: No specimen available.

Color.—As described in Mustela erminea richardsonii except that upper parts about tone 3 of dark Chocolate Brown of Oberthür and Dauthenay, pl. 342; lower throat and chest covered by a large patch of same color as upper parts; color of underparts extending to toes but in interrupted fashion on both fore- and hind-feet; least width of color of underparts averaging, in four males from Prince of Wales Island, 41 (38-49) per cent of greatest width of color of upper parts. Black tip of tail averaging, in 8 males in winter pelage, 65 (59-78) mm. which is 84 (69-92) per cent of length of tail-vertebrae.

From its geographic neighbors alascensis and initis, celenda differs in darker color of upper parts, presence rather than absence of patch of dark color on lower throat and chest, and longer black tip on tail. From haidarum, celenda differs in darker color of upper parts, presence rather than absence of patch of dark color on lower throat and chest, narrower light-colored under parts, black tip of tail averaging less rather than more than nine-tenths of length of tail-vertebrae and ventral face of tail colored like upper parts rather than like underparts.

Skull.—Male (illustrated by 5 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 2.3 (2.2-2.5) grams; basilar length, 39.5 (38.9-40.7) mm.; length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more or less than (about equal to) distance between last upper molar and jugular foramen.

Female.—Complete skull of adult unavailable.

Differences from richardsonii are indicated in the formal description just given. Additional to differences therein noted, celenda differs from initis in larger interorbital and preorbital parts of the skull although dimensions of other parts of the skull and the teeth are about the same or even less. From salva, celenda differs in larger average size in every measurement taken, except for the inner moiety of M1 which is about the same. The skull of celenda is 35 per cent heavier. In relation to the basilar length the skull of celenda is wider, especially in the interorbital and preorbital regions. In comparison with alascensis the tympanic bullae are of approximately the same length; otherwise essentially the same differences obtain as are noted in comparison with salva and the zygomatic breadth is relatively more in celenda. From seclusa, in which the teeth are of comparable size, celenda differs in that every cranial measurement is more and the skull is 28 per cent heavier. Because the skull of celenda is so much longer, its dimensions in other planes are less in relation to the length than in seclusa. M. e. celenda is larger in every part measured than haidarum, 21 per cent heavier, and in relation to the basilar length the interorbital, and preorbital, parts of the skull are smaller, the braincase is shallower, and the skull is relatively wider across the zygomata and mastoid processes. In comparison with kadiacensis, differences are: 26 per cent lighter, skull shorter; in relation to the basilar length, braincase shallower as measured at the anterior end of the basioccipital, tooth-rows shorter but orbitonasal length more. In comparison with arctica all parts measured of the teeth and skull of celenda are smaller and its skull is 34 per cent lighter. In relation to the basilar length, the interorbital breadth of celenda is only slightly less but its skull is narrower across the rostrum and zygomata, the tooth-rows are shorter, and the braincase is shallower.

Remarks.—The late George Willett in the course of his work in Alaska collected most of the known specimens of this strongly differentiated subspecies. In both coloration and cranial characters the distinguishing features are so well marked that the zoölogist could with reason accord full specific rank to celenda. Nevertheless it obviously is an ermine. Also, races from other islands of southeastern Alaska tend to bridge the gap, as regards cranial features, between celenda and the mainland ermine. The specimen from Dall Island agrees in all respects with topotypes. The specimen from Howkan on Long Island is in white winter pelage and the skull has suffered shrinkage from some chemical solution; the reference of this specimen to celenda is tentative.

Specimens examined.—Total number, 25, as follows: Arranged by localities from north to south. Unless otherwise indicated, in U. S. National Museum.

Alaska. Prince of Wales Island: Craig, 18 (10 in Mus. Vert. Zoöl., and 8 in Los Angeles Mus. Hist. Art and Sci.); Kasaan Bay, 2; no locality more definite than the Island itself, 3; Dall Island, Otter Harbor, 1 (Los Angeles Mus. Hist. Art and Sci.). Long Island, Howkan, 1 (Field Mus. Nat. Hist.).

Mustela erminea seclusa Hall

Ermine

Plates , and

Mustela erminea seclusa Hall, Proc. Biol. Soc. Washington, 57:39, June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.

Type.—Male, adult, skull alone; no. 31232, Mus. Vert. Zoöl.; Port Santa Cruz, Suemez Island, Alaska; March 24, 1920; obtained by George Willett.

The skull (plates -) is complete and unbroken. Of the upper incisors only right I3 is present. Otherwise the teeth are present and unbroken.

Range.—Known only from the type locality. See figures , on pages 95, 134.

Characters for ready recognition (only the male known).—Differs from M. e. celenda in basilar length less than 38.2, from M. e. salva, initis and haidarum in zygomatic breadth more than distance between last upper molar and jugular foramen.

Description.—Size and Color.—No external measurements or skins available.

Skull.—Male: See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.8 grams; basilar length, 34.3; length of tooth-rows about the same as length of tympanic bulla; breadth of rostrum measured across lacrimal processes more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior margin of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.

Female.—Skull not available.

From alascensis and salva, seclusa differs in larger teeth, shorter skull, much larger preorbital and interorbital regions, actually as well as in relation to basilar length. Excepting the teeth, which are of about the same size, the same general differences obtain in comparison with initis which, however, is 29 per cent heavier.

From celenda, seclusa differs in smaller skull in all parts measured, being 22 per cent lighter. The teeth are about the same size. In relation to its length the skull of seclusa is much broader and deeper. From haidarum, seclusa differs in: teeth larger; skull shorter and more convex in dorsal outline along median longitudinal axis; in relation to basilar length, skull broader, deeper and braincase relatively shorter.

Remarks.—The characters shown in the one available skull are far outside the limits of individual variation for other known subspecies. Other specimens are much to be desired to ascertain what the "average" individual is like and to learn the characters of the female.

Specimen examined.—One, the holotype.

Mustela erminea haidarum (Preble)

Ermine

Plates , , , , and

Putorius haidarum Preble, Proc. Biol. Soc. Washington, 12:169, August 10, 1898.

Mustela haidarum, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.

Mustela erminea haidarum, Hall, Proc. Biol. Soc. Washington, 57:38, June 28, 1944; Hall, Journ. Mamm., 26:181, July 19, 1945.

Type.—Male, adult, skull, skeleton and skin; no. 94430, U. S. Nat. Mus., Biol. Surv. Coll.; Massett, Queen Charlotte Islands, British Columbia; March 17, 1898; obtained by J. H. Keen; original no. 1800x.

The skull is unbroken and complete except for osseous tissue destroyed in the region of each postorbital process; this is the result of infestation of the frontal sinuses by parasites. The skeleton is complete down to the distal ends of the tibiae; the more distal bones are in the skin. The first, right, upper incisor is missing. Otherwise the teeth all are present and entire.

The skin is in the white, winter pelage but the new under fur is visible along the back and on the head although mostly covered with white hair.

Range.—Queen Charlotte Islands. See figure , page .

Characters for ready recognition.—Differs from M. e. celenda in chest white (not mostly covered by brown patch), proximal two-thirds of under side of tail colored like underparts instead of upper parts, in males basilar length less than 38.2; from M. e. seclusa, in male, in zygomatic breadth less than distance between last upper molar and jugular foramen; from M. e. richardsonii and alascensis, in both sexes, in proximal two-thirds of under side of tail colored like underparts instead of upper parts, interorbital breadth not less than distance from glenoid fossa to posterior margin of external auditory meatus; from M. e. anguinae and fallenda, in both sexes, in light-colored underparts more than half the width of dark-colored upper parts, proximal two-thirds of under surface of tail colored like underparts instead of upper parts, interorbital breadth equal to or more than distance between glenoid fossa and posterior margin of external auditory meatus.

Description.—Size.—Male: Two adults, U.S.N.M., no. 100622, from Cumsheva Inlet, and Amer. Mus. N. H., no. 37411, and the type, measure, respectively, as follows: Total length, 283, 290, 275; length of tail, 70, 75, 60; length of hind foot, 39, 40, 37.

Female: Corresponding measurements of an adult, no. 100624, and a young individual, no. 100623, each from Cumsheva Inlet, are: 252, 250; 63, 61; 31, 32.

Color.—As described in Mustela erminea richardsonii except that underparts not Sulphur Yellow but ranging from near (e) Colonial Buff through Marguerite Yellow to almost pure white; color of underparts extends distally on posterior sides of forelegs and onto toes but in many specimens interrupted at wrist by color of upper parts; color of underparts extends onto proximal three-fourths of under side of tail as length of tail is measured along tail-vertebrae; least width of color of underparts averaging, in 5 males, 79 (66-130) per cent of greatest width of color of upper parts. Black tip of tail in same males averaging 62 (60-70) mm. which is 92 (83-115) per cent of length of tail-vertebrae.

The close correspondence in color-pattern of this weasel with the Arctic races, arctica, polaris, semplei and kadiacensis is noteworthy, and distinguishes it from weasels on the adjacent mainland and adjoining islands to the north and south. The color of the upper parts is darker than in the four Arctic races named.

Skull.—Male (7 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.9 (1.7-2.0) grams; basilar length, 36.7 (35.6-37.5); length of tooth-rows more than length of tympanic bullae; breadth of rostrum measured across lacrimal processes more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior margin of external auditory meatus; zygomatic breadth barely less than distance between last upper molar and jugular foramen.

Female (2 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.3 and 1.4 grams; basilar length, 34.2; length of tooth-rows more or less than (about equal to) length of tympanic bulla; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth not less than distance between glenoid fossa and posterior margin of external auditory meatus.

From richardsonii, haidarum differs in that skull of the male is actually larger in its anterior part (breadth of rostrum, interorbital breadth and orbitonasal length) but all measurements of other parts average less. In relation to the basilar length, the tympanic bulla is shorter but all other measurements are more. In the skull of the female, which is 23 per cent heavier, the width of the tympanic bulla and anteroposterior extent of the inner lobe of M1 are the same; in all other measurements the female of haidarum is larger, and in relation to the basilar length all measurements are more except the depth of the skull at the anterior margin of the basioccipital and the width of the tympanic bulla, which are less. By actual weight the skull of the male is 25 per cent lighter and the skull of the female 24 per cent heavier than in richardsonii. From fallenda and anguinae, haidarum differs in that measurements of the skulls of both sexes either average more, or are uniformly more, with two exceptions. These are the lesser length and breadth of the tympanic bulla, in comparison with males of fallenda, and the dimensions of M1 which are about the same in all three races concerned. The pre- and interorbital parts are larger in relation to the remainder of the skull. The postorbital breadth is actually a third more than in fallenda. In relation to the basilar length, the tympanic bulla is shorter and the braincase deeper than in males of anguinae. The skull of the male is 27 per cent heavier than that of fallenda and 58 per cent heavier than that of anguinae. The skull of the female is 59 and 50 per cent heavier than those of fallenda and anguinae, respectively. Comparison of the skull with those of alascensis, celenda and seclusa has been made in the accounts of those subspecies.

Remarks.—The available specimens of this ermine were obtained by J. H. Keen in 1898, Wilfred H. Osgood and E. A. Lewis in 1900, W. W. Brown in 1914, J. A. Munro in 1917 and 1918, and Allan Brooks in 1920. M. e. haidarum has more claim to full specific status than any other race of ermine because the diagnostic structural features are numerous and individually of relatively great degree. Indeed, individual variation appears not to bridge the gap between any population of haidarum and other subspecies and strong reasons could be advanced for according haidarum the status of a full species. It differs from the subspecies of erminea on the adjoining mainland and adjoining islands to the north and south and agrees with the Arctic races (arctica, polaris, semplei and kadiacensis) in great extent of the color of the underparts, extension of this color onto the underneath side of the tail, long black tip of the tail and general form of the skull including the relatively heavy preorbital region. The color although darker than in the Arctic subspecies, is lighter than in the insular races immediately to the north and south. In combination, the features mentioned could be taken as indication that haidarum is a relict population from a former glacial period. Assuming that it is a relict population, the color may have become slightly darker since that period but the main response appears to have been a decrease in size for this is a much smaller animal than the Arctic ermines. The size is about what would be expected if one were to judge by the slightly larger ermines on the islands of southeastern Alaska to the north and the smaller ermine on Vancouver Island to the south.

The ermines of the islands of southeastern Alaska, excepting possibly the incompletely known seclusa, have fewer characters of the Arctic races and more characters of the races of the adjoining mainland. Therefore, a possible inference is that the distinctive characters of ermines of the Alaskan islands developed with the aid of isolation from stocks which reached the islands after the glacial period. M. e. haidarum may have found its way to the Queen Charlotte Islands in the glacial period.

Specimens examined.—Total number, 17, as follows. Arranged by locality from north to south. Unless otherwise indicated, specimens are in the U. S. National Museum.

British Columbia. Queen Charlotte Islands. Masset, 7 (4, 1, 1); Skidegate, 1; Graham Island, 5 (2, 1, 1); Cumsheva Inlet, 3; no locality more definite than Queen Charlotte Islands, 1.

Mustela erminea anguinae Hall

Ermine

Plates , , , , and

Mustela cicognanii anguinae Hall, Univ. California Publ. Zoöl., 38:417, November 8, 1932.

Putorius cicognanii, Baird, Mamm. N. Amer., p. 161, 1858 (part).

Putorius streatori, Swarth, Univ. California Publ. Zoöl., 10:102, February 13, 1912.

Mustela erminea anguinae Hall, Journ. Mamm., 26:79, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Type.—Male, adult, complete skeleton (no skin); no. 12482, Mus. Vert. Zoöl., French Creek, Vancouver Island, British Columbia; found as a desiccated carcass on May 1, 1910; obtained by Harry S. Swarth.

Range.—Vancouver Island, British Columbia. See figures , pages 95, 149.

Characters for ready recognition.—Differs from M. e. haidarum, in both sexes, in light-colored underparts less than half the width of dark-colored upper parts, proximal two-thirds of under surface of tail colored like upper parts instead of underparts, interorbital breadth less than distance between glenoid fossa and posterior margin of external auditory meatus; from M. e. fallenda, in both sexes, anterior margin of tympanic bullae flush with squamosal rather than projecting from floor of braincase, in males by sagittal crest absent, in females by total length more than 238 and tooth-rows about same length as, instead of longer than, tympanic bulla; from M. e. streatori, in male, by sagittal crest absent and hind foot ordinarily more than 33.5, in female by hind foot more than 27.5, basilar length more than 30.2; from M. e. olympica, in males, by greater average size, hind foot ordinarily more than 33.4 and interorbital breadth ordinarily more than 8.5, in females by larger size, total length more than 235, tail more than 65, hind foot more than 27.5, basilar length more than 30.2.

Description.—Size.—Male: Sixteen adults and subadults yield average and extreme measurements as follows: Total length, 272 (261-284) mm.; length of tail, 81 (74-86); length of hind foot, 35.0 (33.5-36).

Female: Five adults and subadults have corresponding measurements as follows: 247 (241-257); 69 (66-73); 30.0 (28.0-32.0).

Color.—As described in Mustela erminea streatori except that: occasionally white in winter; upper parts about tone 2 of Dark Chocolate of Oberthür and Dauthenay; least width of color of underparts averaging, in 7 adult males, 6 (0-15) per cent of greatest width of color of upper parts. Black tip of tail in same series averaging 37 (26-46) mm. which is 46 (32-54) per cent of length of tail-vertebrae.

Skull.—Male (based on 13 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.2 (1.0-1.3) grams; basilar length, 34.0 (32.5-35.6); length of tooth-rows more or less (usually less) than length of tympanic bulla.

Female (based on 5 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight 0.9 (0.77-1.06) grams; basilar length, 31.5 (30.9-31.8) grams; length of tooth-rows more or less than (approximately same as) length of tympanic bulla; breadth of rostrum more than 30 per cent of basilar length.

The sexual dimorphism in the skull is slight, the skull of the male being only a third heavier than that of the female. In fallenda of the adjacent mainland to the east the male is three-fourths heavier than the female. In comparison with fallenda, males are smaller, averaging less in every cranial and dental measurement taken and by weight are a fifth lighter; sagittal crest absent rather than present; tympanic bullae flush with squamosal rather than projecting below floor of braincase; in relation to basilar length, tympanic bullae smaller, braincase deeper and broader, skull wider interorbitally and across zygomata. Females are larger than in fallenda, and with one exception average larger in every cranial and dental measurement taken, being 6 per cent heavier. The one exception mentioned is the lesser actual length of the tympanic bulla in anguinae, in which the length of the tooth-rows is about the same as, rather than less than, the length of the tympanic bulla. The postorbital breadth is greater than in fallenda and the anterior edges of the tympanic bullae are flush with the squamosals rather than projecting below the floor of braincase. In relation to the skull as a whole the preorbital and interorbital parts are larger.

In comparison with streatori, skulls of males are of about the same size, anguinae being only 9 per cent heavier. The length of the tooth-rows is ordinarily less than, rather than about equal to, the length of the tympanic bulla; sagittal crest wanting rather than present since in anguinae the temporal muscles meet usually only at the posterior end of the braincase instead of all along the midline on its top; tympanic bullae narrower and more nearly flush with squamosal (less protruded from braincase). Relative to the basilar length, the zygomatic breadth is more, the tympanic bullae are narrower, and the braincase is deeper at the anterior end of the basioccipital. The female is 41 per cent heavier than streatori, there being no overlap in most cranial and dental measurements. M1, however, is approximately the same size in each subspecies. The tooth-rows and tympanic bulla are of almost equal length whereas in streatori the length of the tooth-rows is less than that of the bulla.

Differences from olympica, in males, are: M1 shorter; all other measurements of teeth and parts of skull averaging larger; skull 20 per cent heavier; tooth-rows averaging shorter than tympanic bulla rather than about the same; relative to basilar length, braincase deeper at anterior end of basioccipital and tooth-rows shorter. The skull of the female is 64 per cent heavier, larger in every measurement taken without overlap; temporal ridges meeting, rather than separated, at lambdoidal crest; length of tooth-rows about equal to, rather than shorter than, tympanic bulla; in relation to basilar length, skull deeper, orbitonasal length more, mastoid and zygomatic breadths more, and tympanic bullae shorter.

Remarks.—References in the literature to this insular race mostly were under the name streatori until 1932 when in the course of the present study the name anguinae was proposed. A few specimens have been taken by nearly every student of small mammals who has collected on Vancouver Island. Arthur Peake and Herbert Laing have probably collected more specimens than any other two zoölogists.

M. c. anguinae is noteworthy for the slight secondary sexual variation in size; the disparity between the two sexes is less than in any other American subspecies of erminea. By linear measurement the body of the female is only 7 per cent shorter than in the male (178 versus 191 mm.). Linear measurements and weights of the skulls of the two sexes are further indicative of this approximation in size. By weight the skull of the female is only a fourth lighter than that of the male, or, stated in another way, the male's skull is only a third heavier (1.2 versus 0.9 grams).

No geographic variation has been detected between lots of specimens from different parts of Vancouver Island. The one specimen available from Salt Spring Island presents no obvious differences from selected individuals from Vancouver Island.

The winter pelage is more often brown than white. Of 17 specimens seen in winter pelage or in transition pelage, only 6 are white. These 6 are from Comox, Stamp River, Hilliers, Jeune Landing and Port Alice. Of the 34 specimens in brown pelage, 7 have the dark color of the upper parts meeting on the abdomen. Six of the 34 have brown color on the pectoral region. In two, this is a separate patch but in the other four the dark color is a continuation of the upper parts and extends in front of each foreleg over part of the pectoral region, but the two extensions, one from either side, do not meet on the underparts. The color of the lips was recorded in 22 individuals: one had both the upper and lower-lips white; 7 had the upper lips brown and the lower lips white; in 14 both the upper and lower-lips were brown.

Specimens examined.—Total number, 40, listed by localities from north to south as follows. Unless otherwise indicated, specimens are in the National Museum of Canada.

British Columbia. Vancouver Island: Cape Scott, 4; Shushartie, 1; Quatsino, 1; Jeune Landing, 1; Port Alice, 5; Marble Creek, Quatsino Sound, 1; Port Hardy, 5; Sayward, 2; Bear Lake, 4; Bear River, 1; Comox, 4(3); Stamp River, Alberni, 1; Errington, 1; French Creek, 1; Hilliers, 1; Craigs Crossing, 1; Nanaimo, 2; Cowichan Lake, 1; Duncan, 2; Salt Spring Island, 1.

Mustela erminea fallenda Hall

Ermine

Plates , , , , and

Mustela erminea fallenda Hall, Journ. Mamm., 26:79, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Putorius streatori Merriam, N. Amer. Fauna, 11:13, June 30, 1896 (part-Sumas).

Type.—Male, adult, skull and skin; no. 7096, Nat. Mus. Canada; Huntingdon, British Columbia; May 21, 1927; obtained by C. H. Young, original no. 317.

The brown summer skin is well made. The skull (plates -) is complete. Right p2 has the crown broken away; otherwise the teeth all are present and entire.

Range.—On mainland in immediate vicinity of coast from probably opposite Texada Island, British Columbia, south to Lake Whatcom, Washington, and east to Mount Baker Range on International boundary. See figures , on pages 95, 149.

Characters for ready recognition.—Differs from M. e. haidarum, in both sexes, in light-colored underparts less than half the width of dark-colored upper parts, proximal two-thirds of under surface of tail colored like upper parts instead of underparts, interorbital breadth less than distance between glenoid fossa and posterior margin of external auditory meatus; from M. e. richardsonii in both sexes, by upper lips brown rather than white, in males hind foot less than 41 and basilar length less than 38.3, in females hind foot less than 29, basilar length less than 31.4 and breadth of rostrum more, instead of less, than 30 per cent of basilar length; from M. e. invicta, in both sexes, by upper lips brown (not white); in males by skull averaging shorter (basilar length 35.7 versus 37.0); in females by breadth of rostrum more, instead of less, than 30 per cent of basilar length; from M. e. anguinae, in both sexes, by anterior margin of tympanic bulla projecting from floor of braincase rather than flush with squamosal (the difference is slight in females), in males by sagittal crest present, in females by total length less than 238 and tooth-rows longer than, instead of about same length as, tympanic bulla; from M. e. streatori, in both sexes, by black tip of tail more than half of length of tail-vertebrae, in males hind foot more than 33.7, tympanic bulla longer than, instead of about same length as, upper tooth-rows; weight of skull more than 1-1/4 grams, in females weight of skull more than 0.7 grams, length of lateral side of P4, 4 mm. or more; from M. e. olympica, in males, length of hind foot more than 33, black tip of tail more than 36.5 mm., weight of skull more than 1.2 grams, basilar length more than 33.5, in females length of hind foot more than 25.5, weight of skull more than 0.66 grams, basilar length more than 28.4; from M. e. gulosa, in both sexes, by anterior margin of tympanic bulla projecting below floor of braincase rather than flush with squamosal (the difference is slight in females), in males hind foot more than 33.5, weight of skull more than 1-1/4 grams, basilar length more than 33.9, in females by total length more than 222, hind foot longer than 26, weight of skull more than 0.7 grams, basilar length more than 29.

Description.—Size.—Male: Seven adult topotypes yield average and extreme measurements as follows: Total length, 278 (249-305); length of tail, 77 (69-81); length of hind foot, 36.5 (34-40). A male topotype of unknown age weighed 113 grams.

Female: Two adult topotypes, with actual measurements in parentheses, average as follows: Total length, 232 (228-236); length of tail, 60 (57-62); length of hind foot, 27 (27-27). An adult from Morovitz Guard Station, Wash., weighed 54 grams.

Color.—Winter pelage rarely white, brown pelage indistinguishable from summer pelage except for slightly more smoky tinge in winter in specimens from some localities; otherwise as described in Mustela erminea streatori except that least width of color of underparts averaging, in seven adult topotypes, 18 (0-37) per cent of greatest width of color of upper parts. Black tip of tail averaging, in same series, 45 (38-52) mm. which is 58 (53-65) per cent of length of tail-vertebrae.

In comparison with richardsonii and invicta, fallenda differs in darker color of upper parts and their extension at the expense of the light-colored underparts which are narrower by a half. In correlation with this restriction in area of the light-colored underparts, the upper lips are brown instead of white. In comparison with anguinae, olympica and streatori, the longer black tip on the tail is the principal difference in color. From gulosa, fallenda differs in slightly darker color of upper parts and in narrow underparts, the width of the same being only about a fifth instead of a third of the width of the dark-colored upper parts.

Skull.—Male (based on 7 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.5 (1.3-1.7) grams; basilar length, 35.7 (34.3-38.2).

Female (based on 6 ads.): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 0.85 (0.73-1.0) grams; basilar length, 30.6 (29.4-31.7); breadth of rostrum more than 30 per cent of basilar length.

In comparison with richardsonii, skulls of males differ as follows: averaging smaller in every measurement taken with no overlap in several dimensions; 40 per cent lighter; in relation to basilar length, rostrum (orbitonasal length) longer and skull slightly broader interorbitally. Females average smaller in every cranial and dental measurement taken with no overlap in basilar length, length of tooth-rows and length of tympanic bulla; 22 per cent lighter; breadth of rostrum more, rather than less, than 30 per cent of basilar length; in relation to basilar length, pre- and interorbital parts of skull larger, and mastoid breadth more.

Differences from males of olympica are: size larger with no overlap in most measurements; 50 per cent heavier; tympanic bullae longer than upper tooth-rows rather than of about equal length; in relation to basilar length, rostrum shorter, braincase wider and deeper, zygomata more expanded. Females are larger with no overlap in most measurements; 35 per cent heavier; in relation to basilar length, pre- and interorbital regions narrower, braincase deeper and wider across mastoids.

Differences from streatori, in males, are: skull averaging larger in every cranial and dental measurement taken; 36 per cent heavier; tympanic bulla longer than, instead of about same length as, upper tooth-rows. In females the inner lobe of M1 is shorter anteroposteriorly; otherwise all measurements of fallenda average larger and it is 33 per cent heavier; rostrum and interorbital region broader in relation to remainder of skull.

In comparison with gulosa, skulls of males differ as follows: averaging larger in every measurement taken with no overlap in several dimensions; 50 per cent heavier; tympanic bullae with anterior margins projecting slightly below squamosals rather than flush with same; length of bulla more than, rather than about same as, that of upper tooth-rows. Considering the great difference in size, the relative proportions are remarkably alike. In females, length of inner lobe of M1 about the same; otherwise averaging larger in every measurement taken; 44 per cent lighter; relative to basilar length, tooth-rows longer, skull wider across zygomata and mastoids, rostrum and interorbital regions slightly narrower, skull shallower in plane of last upper molars.

Comparisons with haidarum, invicta and anguinae are made in accounts of those subspecies.

Remarks.—Until the name fallenda was proposed in the course of the present study, most of the specimens of this race were assigned to streatori.

Intergradation with streatori is complete as it is also with invicta and richardsonii, in other words with each of the subspecies whose ranges meet that of fallenda. In color and in size the difference is least between streatori and fallenda. As between fallenda and invicta the size is not greatly different and the intergradation in color is gradual. Between fallenda and richardsonii intergradation is somewhat different and to fully appreciate its nature we should remember that the color of fallenda resembles that of the saturate coastal races, streatori, anguinae and olympica although the black tip of the tail is longer. In this latter feature and in several cranial details, as well as in greater degree of secondary sexual variation in size, fallenda resembles richardsonii. Because the two differ more than do most subspecies of ermine whose ranges meet, some of the intergrades at first inspection appear to be widely different from either parent stock. For example, specimens from Alta Lake, British Columbia, may give this impression because the combination of large size and dark color suggests a kind of ermine different from either fallenda or richardsonii. In no instance, however, has there been found in these intergrades any character other than those occurring in one or the other of the two parent races.

Along the coast in the north part of the geographic range assigned to fallenda, some specimens nearly typical of richardsonii have been taken so near to the place where fairly typical fallenda was obtained that I have doubted whether there is intergradation in the usual fashion in this area; more specimens will have to be obtained from this coastal area to resolve the doubt one way or the other.

The winter pelage is brown in all specimens at most localities. The only white pelage seen was in each of three specimens from Glacier, Whatcom County, Washington. A fourth specimen from there is in brown winter pelage. At any one locality there is much variation in the degree to which the dark color of the upper parts encroaches on the area that in most other races is light-colored. An extreme degree of encroachment is shown by a specimen taken on December 1, 1935, by R. A. Cummings, at Vancouver, British Columbia, in which the light color occurs only in three restricted areas, the chin, the throat and the lower breast; otherwise the coat is brown. There are other specimens, for instance from the type locality, which differ mainly in having an additional white spot in the inguinal region. The opposite extreme, in a specimen also from the type locality, is where the least width of the light-colored underparts on the abdominal region is a third of the circumference of the body. The two extremes are connected by a dozen intermediate stages. Of 64 specimens in which the color of the lips was carefully examined, one, from Vancouver, has both the upper and lower-lips brown; 9 have both the upper and lower-lips white; and 54 have the upper lips brown and the lower lips white.

Specimens examined.—Total number, 72, arranged by localities from north to south. Unless otherwise indicated, specimens are in the National Museum of Canada.

British Columbia. Horseshoe Lake, Stillwater, 2; Vancouver, 1; Point Grey, 1; Port Moody, 5; Chilliwack, 8 (2, 4, 1); Sumas, 19 (18, 1); Thurstons Ranch, 2; Cultus Lake, 2; Mt. Baker Range, 5; Lihumption Park, 1; Huntingdon, 14; Tami Hy Creek, 1.

Washington. Whatcom County: Semiahmoo, 1; New Whatcom, 1; Lake Whatcom, 2; 5 mi. W Glacier, 1; Glacier (3 at 900 ft.), 4; E Side Easton Glacier, Mt. Baker, 1; Morovitz Guard Station, 831 ft., 1.

Mustela erminea olympica Hall

Ermine

Plates , , , , and

Mustela erminea olympica Hall, Journ. Mamm., 26:81, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Mustela rixosa, Svihla and Svihla, Murrelet, 13:24, January, 1932.

Mustela rixosa rixosa, Svihla and Svihla, Murrelet, 14:39, May, 1933.

Type.—Male, adult, skull and skin; no. 90738, U. S. Nat. Mus., Biol. Surv. Coll.; near head of Soleduc River, 4500 ft., Olympic Mountains, Clallam County, Washington; April 28, 1897; obtained by Vernon Bailey, original no. 6213.

The skin is well prepared and in good condition. The skull (plates -) is unbroken and the teeth all are present and entire.

Range.—Olympic Peninsula, Washington, south to Olympia. See figures , on pages 95, 149.

Characters for ready recognition.—Differs from M. e. anguinae, in males, by lesser average size, hind foot ordinarily less than 33.4, and interorbital breadth ordinarily less than 8.5, in females by smaller size, total length less than 235, tail less than 65, hind foot less than 27.5, basilar length less than 30.2; from M. e. fallenda, in males, by length of hind foot less than 33, black tip of tail less than 36.5, weight of skull less than 1.2 grams, basilar length less than 33.5, in females length of hind foot less than 25.5, weight of skull less than 0.6 grams, basilar length less than 28.4; from M. e. streatori by smaller size, in males hind foot less than 33.0, basilar length ordinarily less than 32.5, in females by hind foot ordinarily not longer than 24, by breadth of rostrum less than 8.6, depth of braincase at posterior border of upper molars less than 7.6.

Description.—Size.—Male: Twelve individuals of adult proportions yield average and extreme measurements as follows: Total length, 243 (205-269); length of tail, 65 (60-74); length of hind foot, 31 (29-32).

Female: Corresponding measurements of six females are: 196 (188-208), 52 (45-60?), 23.4 (22.7-24.0). An adult weighs 30 grams.

Color.—As described in Mustela erminea streatori except that least width of color of underparts averaging, in 12 males of adult proportions, 5 (0-11) per cent of greatest width of color of upper parts. Black tip of tail averaging, in same series, 26 (20-35) mm., which is 40 (31-58) per cent (average the same as in streatori) of length of tail-vertebrae.

Skull.—Male (based on 5 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.0 (0.9-1.1) grams; basilar length, 31.8 (30.6-32.5); length of tooth-rows more or less than (about equal to) length of tympanic bulla.

Female (illustrated by 3 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 0.55 (0.52-0.58) grams; basilar length, 27.1 (26.7-27.5); breadth of rostrum more than 30 per cent of basilar length.

In comparison with streatori, skulls of corresponding sex average smaller in every measurement taken with no overlap in most of those of females. Exception is to be made for the inner lobe of M1 in males where the size is the same. By weight males are smaller by 10 per cent and females by 14 per cent. In relation to other parts of the skull the tympanic bullae are narrower and in females they are shorter as well. Comparison with anguinae and fallenda has been made in the accounts of those subspecies.

Remarks.—The smaller size, especially of females, is the principal feature distinguishing this race from streatori. On the basis of available data the female of olympica is smaller than that of any other race and hence is the smallest adult weasel of the species erminea, in either the Old World or in America.

Intergradation with streatori is indicated by specimens from the southern end of Puget Sound. These specimens are intermediate in size between typical examples of the two races concerned.

The color of the upper parts is uniform and the color pattern varies less than in geographically adjoining races. The white color of the underparts is restricted to a thin line on the abdominal region, but widens out posteriorly in the inguinal region and anteriorly over the pectoral region, throat, chin and lower lips. The upper lips are brown. The brown of the upper parts extends around in front of each foreleg, the two brown areas not quite meeting on the lower throat. The above description applies to each of the 19 specimens examined with regard to these details. Every specimen seen in the winter coat was brown, not white.

Specimens examined.—Total number, 20, arranged by counties from north to south. Unless otherwise indicated, specimens are in the U. S. National Museum.

Washington. Clallam County: Clallam Bay, 2 (1, 1); Elwha, 2; Johnsons Ranch, 1; Happy Lake, 1; Boulder Lake, 2; near head of Soleduc River, 4500 ft., 1; 12 mi. S Port Angeles, 1. Jefferson County: Hayes Cr., 2000 ft., Elwha River, 2; head N Fork Quinault River, 4000 ft., 1; Duckabush, 3; N Fork Skokomish River, 1. Mason County: Lake Cushman, 2; 4 mi. S Olympia, 1.

Mustela erminea streatori (Merriam)

Ermine

Plates , , , , and

Putorius streatori, Merriam, N. Amer. Fauna, 11:13, pl. 2, figs. 5, 5a, 6, 6a, June 30, 1896.

Putorius cicognanii, Baird, Mamm. N. Amer., p. 161, 1858 (part unless no. 2395 was a female of M. frenata).

Putorius pusillus, Baird, Mamm. N. Amer., p. 159, 1858 (part).

Putorius (Gale) vulgaris, Coues, Fur-bearing animals, p. 102, 1877 (part).

Mustela streatori streatori, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Grinnell, Univ. California Publ. Zoöl., 40:101, September 26, 1933.

Mustela cicognanii streatori, Hall, Murrelet, 12:22, January, 1931; Hall, Univ. California Publ. Zoöl., 38:417, November 8, 1932.

Mustela erminea streatori, Hall, Journ. Mamm., 26:77, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Mustela rixosa, Beer, Journ. Mamm., 29:296, August 31, 1948.

Type.—Male, adult, skull and skin; no. 76646, U. S. Nat. Mus., Biol. Surv. Coll.; Mount Vernon, Skagit Valley, Skagit County, Washington; February 29, 1896; obtained by D. R. Luckey, original no. 3.

The skull is unbroken and the teeth all are present and entire. The skin, in brown winter pelage, is stuffed and in good condition.

Range.—Western Washington along eastern side of Puget Sound, western Oregon from the Cascades to the coast, and northwestern California south in the humid coastal district nearly to the Golden Gate. See figures , on pages 95, 149.

Characters for ready recognition.—Differs from M. e. anguinae, in male, by sagittal crest present and hind foot ordinarily less than 33.5, in female by hind foot less than 27.5, basilar length less than 30.2; from M. e. fallenda, in both sexes, by black tip of tail less than half of length of tail-vertebrae, in males hind foot less than 33.7, tympanic bulla about same length as, instead of longer than, upper tooth-rows; weight of skull less than 1-1/4 grams, in female weight of skull less than 0.7 grams, length of lateral side of P4 less than 4 mm.; from M. e. olympica, by larger size, in males hind foot more than 33.0, basilar length ordinarily more than 32.5, in females by hind foot ordinarily longer than 24, by breadth of rostrum more than 8.6, depth of braincase at posterior border of upper molars more than 7.6; from M. e. gulosa and muricus, in both sexes, by upper lips brown (not white), light color of underparts extending down hind leg no farther than knee, depth of skull at posterior border of upper molars more than 7.7 in females and ordinarily more than 9.6 in males, further from muricus by tail more than 62 in males and more than 49 in females; from M. e. invicta by upper lips white (not brown), in males hind foot more than 36 and basilar length more than 35, in females hind foot more than 29.5 and basilar length more than 30.5.

Description.—Size.—Male: Twelve adults from Blaine and Tillamook, Oregon, yield average and extreme measurements as follows: Total length, 255 (245-275); length of tail, 72 (64-80); length of hind foot, 31.5 (30.0-33.5).

Female: Seven adults from Blaine and Tillamook, Oregon, yield average and extreme measurements as follows: Total length, 214 (193-230); length of tail, 55 (50-63); length of hind foot, 25 (24-27).

Color.—Winter and summer pelages indistinguishable; upper parts uniform and ranging from Raw Umber to slightly darker (16n), and about tones 1 to 3 of Dark Chocolate of Oberthür and Dauthenay, pl. 342; underparts white, in summer rarely with a faint buffy suffusion in pectoral region; color of underparts extends from chin, and often lower lips, posteriorly to inguinal region, distally on posterior sides of forelegs onto antipalmar faces of toes (sometimes interrupted at and above wrist) and on medial sides of hind legs hardly to knee. Least width of color of underparts averaging, in twelve adults from Blaine and Tillamook, 10 (0-47) per cent of greatest width of color of upper parts. Black tip of tail, in same series, averaging 28 (24-33) mm. which is 40 (34-47) per cent of length of tail-vertebrae.

Skull.—Male (based on 12 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.1 (1.0-1.2) grams; basilar length, 33.2 (32.5-33.8); length of tooth-rows more or less than (about same as) length of tympanic bulla.

Female (based on 7 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 0.64 (0.60-0.67) grams; basilar length, 28.5 (27.6-29.5); breadth of rostrum more than 30 per cent of basilar length.

Comparison with anguinae, fallenda, olympica, gulosa and muricus is made in accounts of those subspecies.

Remarks.—This weasel is rare in collections and the best material of it was obtained by Alex Walker in Tillamook County, Oregon, where he resides. The almost ideal series of 30 specimens showed the range of secondary sexual, age, and individual variation expectable in the small ermines of the Pacific Coast of the United States and was the means of allowing satisfactory decision on questions of classification in the related subspecies in which individuals are of comparable size.

Intergradation with each of the geographically adjoining subspecies, olympica, fallenda, invicta, gulosa and muricus is shown by specimens examined. With the last mentioned subspecies, intergradation is shown by two specimens from as far south as Siskiyou County, California, assigned to muricus.

The application of the name streatori is difficult because it was based on a specimen from a place where two clines cross. The north-south cline is one of size which decreases to the south. The east-west cline is one of intensity of color, the westernmost (coastal) population being the most intensely colored. The type locality of streatori is at the place where two lines perpendicular to one another, and representing the two clines, cross. This intersection is near the place where the ranges of several subspecies meet. The nomenclatural question is, to which one of 6 subspecies should the name streatori apply. Specimens from barely within the geographic boundaries of four of these subspecies so closely resemble topotypes of streatori that a student with material at his disposal from only the area about Puget Sound naturally would apply the name streatori to all of his specimens, and knowing even of the arrangement adopted in the present account the student will have difficulty in identifying his specimens according to it. Not only will the student find the arrangement difficult, but probably unsatisfactory if he thinks of streatori as being the kind of animal represented by topotypes. I conceive of topotypes of streatori as being nontypical of the subspecies; they are intergrades with fallenda. My aim was initially to work out the geographic ranges of subspecies and only subsequently to apply names, according to which type localities fell within the previously determined geographic ranges. By this procedure no greater weight was given to a holotype and to topotypes than to specimens from any other locality.

Of the 40 specimens seen in winter pelage, only one is white. It is from Darrington in the Cascade Mountains of Washington. The 39 others are brown and I doubt that the white pelage ever occurs in the low coastal territory included within the geographic range of streatori. This subspecies resembles anguinae and olympica in the great extension of area of the dark-colored upper parts at the expense of the area of the light-colored underparts. The usual arrangement is one where the brown of the two sides nearly meets on the midventral line leaving a sizable, inguinal area of light color connected by a thin line to the sizable area of light color on the pectoral region. The light color of the pectoral area ordinarily is continuous with the light-colored area of the throat and chin but the dark color of the upper parts extends around in front of each foreleg. These extensions of dark color meet on the chest in only 2 of the 56 specimens examined in this regard. Across the abdomen the dark color is continuous in 4 of the 56 specimens. The lower lips are brown instead of white in only 3 individuals and in 2 of these the lip of one side is brown and its opposite is white. The variation in color-pattern is less than in anguinae or than in fallenda.

Specimens examined.—Total number, 63, arranged alphabetically by states, then by counties from north to south in each state. Unless otherwise indicated, specimens are in the U. S. National Museum.

California. Humboldt County: 10 mi. NE Carlotta, 1. Mendocino County: Russian Gulch State Park, 1. Sonoma County: Mouth of Gualala River, 1.

Oregon. Clatsop County: Astoria, 1. Tillamook County: Tillamook, 16 (14, 1); Blaine, 12 (7, 2, 1, 2). Washington County: Beaverton, 1; Forest Grove, 1. Clackamas County: Oregon City, 1. Lincoln County: Newport, 1. Linn County: Sico, 1. Lane County: Vida Fish Hatchery, 2; McKenzie Bridge, 1; Mercer, 1. Klamath County: Deschutes River, 6 mi. E Crescent Lake, 1. Douglas County: Gardiner, 1. Curry County: Port Orford, 1; Gold Beach, 2.

Washington. Skagit County: N end Whidby Island opposite Deception Pass, 1; Hamilton, 4; Mt. Vernon, 3. Snohomish County: Oso, 550 ft., 1; Darrington, 600 ft., 1. Pacific County: Wallicut River, 2 mi. E Ilwaco, 1. Wahkiakum County: 4 mi. E. Skamokawa, 3. Cowlitz County: 4 mi. E mouth Kalama River, 2; 6 mi. E mouth Kalama River, 1. Skamania County: 15 mi. N Govt. Springs, 1300 ft., 1.

Mustela erminea gulosa Hall

Ermine

Plates , , , , and

Mustela erminea gulosa Hall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Putorius streatori Merriam, N. Amer. Fauna, 11:14, June 30, 1896.

Type.—Male, subadult, skull and skin; no. 81998, U. S. Nat. Mus., Biol. Surv. Coll.; Trout Lake, Klickitat County, Washington; February 3, 1897; obtained by P. Schmid, original no. 147.

The skin is in brown winter pelage, and appears to have been made up from a skin split along the midventral line from the anus to the forelegs. It probably was dried by a trapper, is well made, and lacks a patch of hair on the left flank but otherwise is in good condition. The skull lacks the central part of the left zygomatic arch and the posterior two-thirds of the right one. The right m2 is represented only by an abortive stump or the broken root, and i1 and i2 on each side are absent; otherwise, the teeth all are present and entire.

Range.—Cascades of Washington from northeastern King County south to Mount Adams. See figures , on pages 95, 149.

Characters for ready recognition.—Differs from M. e. invicta and fallenda, in both sexes, by anterior margin of tympanic bulla flush with squamosal rather than projecting below floor of braincase (difference slight in females), in males hind foot less than 33.5, weight of skull less than 1-1/4 grams, basilar length less than 33.9, in females by total length less than 222, hind foot shorter than 26, weight of skull less than 0.7 grams, basilar length less than 29; from M. e. muricus, in both sexes, by upper parts darker, tone 4 of Chocolate or darker (see description of color), least width of light-colored underparts averaging one-third instead of approximately two-thirds of greatest width of dark-colored upper parts, in males, on the average, tail more than 65, weight of skull more than 0.90 grams, basilar length more than 30.8 mm.; from M. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind legs below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males.

Description.—Size.—Male: One adult and four subadults from Mount Rainier yield average and extreme measurements as follows: Total length, 253 (238-266); length of tail, 75 (70-83); length of hind foot, 31.5 (30-33). Corresponding measurements of 9 subadults from Trout Lake are: 257 (233-282); length of tail, 76 (56-83); length of hind foot, 30.2 (26-33).

Female: Of adults, 2 from Mount Rainier and 2 from Trout Lake measure as follows: Total length, 202, 203, 216, 210; length of tail, 54, 52, 57, 51; length of hind foot, 24, 24, 25, 24. The averages for these females are 208, 54, 24.3.

Color.—As described in Mustela erminea richardsonii except that color sometimes brown in winter (with more smoky tinge than summer coat); upper parts ranging from tone 2 through tones 3 and 4 of Dark Chocolate (pl. 342) into tone 4 of Chocolate (pl. 343) of Oberthür and Dauthenay; underparts (always white in winter) in summer Sulphur Yellow or more whitish; least width of color of underparts averaging, in 5 males from Mount Rainier, 31 (18-45) per cent of greatest width of color of upper parts. Black tip of tail, in same series, averaging 34 (29-40) mm., which is 45 (41-50) per cent of length of tail-vertebrae.

Skull.—Male (based on 2 ad. and 13 sad.): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 1.0 (0.95-1.16) grams; basilar length, 32.3 (30.9-33.4); length of tooth-rows more or less than (about equal to) length of tympanic bulla.

Female (illustrated by 5 adults): See measurements and plates -. As described in Mustela erminea richardsonii except that: Weight, 0.59 (0.53-0.65) grams; basilar length, 28.1 (27.8-28.4); breadth of rostrum ordinarily more than 30 per cent of basilar length.

In comparison with streatori, skulls of males and females average smaller in every cranial measurement taken. Teeth of about same size and males 9 per cent, and females 8 per cent, lighter. In relation to basilar length, skull of female shallower, tympanic bullae slightly shorter and, on the average, zygomata less expanded.

In comparison with muricus, males average larger in every measurement taken; 23 per cent heavier; in relation to other dimensions, braincase shallower at anterior end of basioccipital. Females are of about equal size; in relation to other dimensions, braincase shallower and mastoid and zygomatic breadths less.

Comparisons with invicta and fallenda have been made in the accounts of those subspecies.

Remarks.—This is not a strongly marked race and in most of the characters used for differentiating it from other races it resembles either streatori to the west or muricus to the southeast. Nevertheless, there is a geographic area, the southern Cascades of Washington, throughout which individual characters are combined in essentially the same way and there are a few features, for instance, smaller skull of the female, in which gulosa differs from either of its close relatives. In view of these circumstances and because the animals can not well be included in the subspecies streatori or muricus, gulosa is recognized as distinct. The races gulosa and olympica are what might be termed weakly differentiated subspecies in contrast to the strongly differentiated subspecies streatori and muricus.

Of the 21 specimens in winter pelage, 17 are white and four are brown. The brown winter coat is distinctly paler, with more of a smoky tinge, than the brown summer pelage. The light-colored underparts are narrower than in the subspecies immediately to the east but are wider than in the coastal forms to the west. The dark color of the upper parts extends onto the chest in front of the forelegs, as in the coastal forms, in only one of the 13 specimens in summer pelage and in it on one side only. The black tip of the tail is short as in the coastal forms. One specimen is in transitional pelage. It has acquired approximately half of the white winter pelage and was taken on October 12, 1897, at Keechelus Lake.

Specimens examined.—Total number, 38, arranged by counties from north to south. Unless otherwise indicated, specimens are in the U. S. National Museum.

Washington. King County: 2 mi. E Skykomish, 2. Kittitas County: Keechelus Lake, 3 (1); Martin, 1; Easton, 3. Pierce County: James Lake, 4370 ft., Mt. Rainier, 1; Glacier Basin, 5935 ft., Mt. Rainier, 1; Meslers Ranch, 2000 ft., 1 mi. W Rainier Park, 1. Lewis County: Mt. Rainier Nat'l Park, 5 (1 each from: Paradise Park, 5400 ft.; Reflection Lakes, 4900 ft.; Ohanapecosh [Hot] Springs, 2000 ft.; Tahoma Creek, 1; Bear Prairie); also in Mt. Rainier Nat'l Park, Longmire, 3 (1, 1). Skamania County: Mt. St. Helens, 6000 ft., 1. Klickitat County: Trout Lake, 18.

Mustela erminea muricus (Bangs)

Ermine

Plates , , , , and

Putorius (Arctogale) muricus Bangs, Proc. New England Zoöl. Club, 1:71, July 31, 1899.

Putorius streatori leptus Merriam, Proc. Biol. Soc. Washington, 16:76, May 29, 1903. Type from Silverton, San Juan County, Colorado.

Putorius muricus, Stephens, California Mammals, p. 248, 1906.

Putorius cicognani, Taylor, Univ. California Publ. Zoöl., 7:298, June 24, 1911.

Mustela streatori leptus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Bailey, N. Amer. Fauna, 35:48, September 5, 1913; Dixon, Journ. Mamm., 12:72, February 12, 1931; Whitlow and Hall, Univ. California Publ. Zoöl., 40:246, September 30, 1933.

Mustela muricus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Kellogg, Univ. California Publ. Zoöl., 12:358, January 27, 1916.

Mustela cicognanii lepta, Dice, Journ. Mamm., 1:12, November 28, 1919; Hall, Mamm. Nevada, p. 184, July 1, 1946.

Mustela rixosa, Seton, Journ. Mamm., 14:70, February 14, 1933.

Mustela cicognanii leptus, Miller, Journ. Mamm., 14:368, November 13, 1933; Bailey, N. Amer. Fauna, 55:293, August 29, 1936.

Mustela erminea murica, Hall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.

Type.—Male, young, skull and skin; no. 9146, collection of E. A. and O. Bangs in Mus. Comp. Zoöl.; Echo, 7500 ft., El Dorado County, California; July 15, 1897; obtained by W. W. Price and E. M. Nutting.

The skull has a fracture along the sagittal suture and fractures on the left side of the braincase but these have been glued, and no part of the skull is missing except in the region of the right P4 which part has been shot away. On the left side m2 never developed. Excepting this tooth and the right P4, all the teeth are present and entire. The skin is well made but has the soles of the hind feet turned up.

Range.—Near 5300 feet (Denver) to 11000 feet (Santa Fe Baldy); typically boreal but taken in Upper Sonoran Life-zone in winter at Denver; from central and southwestern Montana, southern Idaho, and Blue Mountains of southeastern Washington southward east of the Cascade Divide through the Salmon River Mountains and Sierra Nevada at least into Fresno County of California, in the Great Basin to central Nevada, in the Rocky Mountains into northern New Mexico; eastward to the Black Hills. See figure on page .

Characters for ready recognition.—Differs from M. e. invicta by hind foot less than 36 and basilar length less than 35 in males and by hind foot less than 29.5 and basilar length less than 30.5 in females; from M. e. gulosa, in both sexes, by upper parts lighter, tone 2 of Chocolate or lighter (see description of color), least width of light-colored underparts averaging about two-thirds instead of one-third of greatest width of dark-colored upper parts, in males, on the average, tail less than 65, weight of skull less than 0.90 grams, basilar length less than 30.8 grams; from M. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind leg below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males, tail less than 62 in males and less than 49 in females.

Description.—Size.—Male: An adult from Black Butte, California, measures: Total length, 227; length of tail, 55; length of hind foot, 27. Corresponding measurements of another from Wheeler Peak, Nevada, are: 220, 56, 26. Two subadults from Colorado, one from Crested Butte and another from Coventry, measure, respectively, as follows: 238, 227; 66, 60; 30, 30. An adult from Wheeler Peak, Nevada, weighs 57.7 grams and another from 2 mi. W Black Butte, Calif., 54.5 grams.

Female: Two adults from Teton County, Wyoming, measure: Total length, 205, 200; length of tail 52,—; length of hind foot, 23, 23.7. A subadult from 9-1/2 mi. E Pocatello, Idaho, measures: 197, 50, 25. An adult from Wheeler Peak, Nevada, has corresponding measurements of 190, 42, 23, and weighs 33.8 grams.

Color.—As described in Mustela erminea richardsonii except that upper parts tone 2 or lighter of Chocolate of plate 343 of Oberthür and Dauthenay; underparts white, Pale Buff or with faint wash of Sulphur Yellow; least width of color of underparts in male from Black Butte and one from Wheeler Peak, amounting to 65 and 59 per cent of greatest width of color of upper parts. Black tip of tail, respectively, 28 and 33 mm., which amounts to 51 and 59 per cent of length of tail-vertebrae. In two adult females, one from Teton County, Wyoming, and one from Wheeler Peak, Nevada, the least width of the underparts amounts to 55 and 60 per cent of the greatest width of color of upper parts. Black tip of tail, respectively, 23 and 19 mm., which amounts to 44 and 45 per cent of length of tail-vertebrae.

From the other subspecies of small-sized weasels of more northwestern occurrence, namely anguinae, fallenda, olympica, streatori and gulosa, muricus differs in lighter color of upper parts, wider light-colored underparts and relatively longer black tip of tail.

Skull.—Male (illustrated by 5 adults in table of measurements, which see): See plate . As described in Mustela erminea richardsonii except that: Weight, 0.78 (Wheeler Peak) and 0.85 (Black Butte) grams; basilar length, 30.6 (29.8-31.2); length of tooth-rows more or less than (approximately equal to) length of tympanic bulla.

Female (illustrated by 6 adults in table of measurements, which see): See plates -. As described in Mustela erminea richardsonii except that: Weight, 0.60 (0.575-0.645); basilar length, 28.0 (27.3-29.4); breadth of rostrum approximately 30 per cent of basilar length.

In comparison with streatori, males average smaller in every measurement taken with no overlap in most dimensions; 25 per cent lighter; anterior margin of tympanic bulla more nearly flush with squamosal, that is to say less protruded from braincase; in relation to other dimensions of skull, braincase shallower anteriorly (at plane of last molars) and deeper posteriorly (at anterior end of basioccipital). Females average smaller in every measurement taken except mastoid and zygomatic breadths which are actually more; 6 per cent lighter; in relation to other parts of skull, preorbital and interorbital parts slightly smaller; in relation to length of skull, braincase shallower. Comparison with invicta and gulosa is made in the accounts of those subspecies.

Remarks.—The smallest males of the entire species are of this subspecies and the females of it are barely larger than those of olympica and gulosa and hence are among the three smallest. The material now available consists only of one or a few specimens from each of several widely separated localities. If as many specimens per unit area were available as there are of the species M. erminea from southern British Columbia, geographic variation warranting the division of muricus into more than one subspecies might be revealed. Evidence pointing in this direction is comprised in the pale color and small size of the pair of adults from Wheeler Peak on the eastern border of Nevada; the suggestion is that there is a distinct pale race of small individuals in the isolated spots of boreal life-zone in the mountains of the desert. The color and size of the specimens from the Toyabe Mountains, and that from the Pine Forest Mountains, both places also in Nevada, nevertheless, lend no support to this suggestion. Comparison of specimens from the Rocky Mountains of Colorado with those from the Sierra Nevada of California gives no basis for recognizing more than one subspecies. Therefore, Putorius streatori leptus Merriam with type locality at Silverton, San Juan County, Colorado, falls as a synonym of the earlier named Putorius (Arctogale) muricus Bangs with type locality at Echo, El Dorado County, California. Furthermore, specimens from northern New Mexico, the southernmost known area of occurrence for the subspecies (and for the species), are as large as specimens from far north in the range of the subspecies, say, in northwestern Wyoming; there is therefore no evidence of progressive decrease in size to the southward as in advance of study I supposed existed in muricus. This erroneous supposition was held because I knew that there was a decrease in size to the southward in the species as a whole and also in each of the subspecies richardsonii and invicta directly to the north of muricus.

Intergradation with invicta is shown by specimens from southwestern Montana. Where the margins of the geographic ranges of invicta and muricus approach one another elsewhere, low-lying territory, zonally unsuited to the existence of the species, occurs along the Snake and Columbia rivers, and precludes any chance of intergradation except around the head of the Snake River Plains. Two specimens, here referred to muricus, from Siskiyou County, California, in both color and cranial characters, are intergrades with streatori and might be referred with almost equal propriety to streatori.

Specimens examined.—Total number, 52, arranged alphabetically by states, then by counties from north to south within each state. Unless otherwise indicated, specimens are in the Museum of Vertebrate Zoölogy, University of California at Berkeley.

California. Siskiyou County: head of Rush Creek, 6400 ft., 1; Castle Lake, 5434 ft., 1. Tehama County: 2 mi. W Black Butte, 6800 ft., 1. Placer County: ridge W of Tahoe Pines, Lake Tahoe, 1; Blackwood Creek, 6250 ft., near Tahoe Pines, 1. El Dorado County: Fallen Leaf Lake, 6500 ft., 1; Echo, 1. Tuolumne County: Ten Lakes, 9200 ft., Yosemite Park, 1. Mariposa County: Vogelsang Lake, 10350 ft., Yosemite Park, 1. Mono County: Mammoth, 1.

Colorado. Rio Blanco County: Marvine, 1. Boulder County: Camp Albion, 10600 ft., 1; Boulder, 1. Denver County: Denver, 1. Park County: Jefferson, 1. Gunnison County: near Placita in Gunnison County, 1; Crested Butte, 9000 ft., 3 (1, 2). El Paso County: Turkey Creek, SW Colorado Springs, 6000 ft., 1. Chaffee County: Arbourville, 1; Hancock, 1. Montrose County: Coventry, 6800 ft., 1. San Juan County: Silverton, 1; in San Juan County above timberline, 1.

Idaho. Bannock County: West Fork of Rapid Creek, 9-1/2 mi. E Pocatello, 1.

Montana. Meagher County: Camas Creek, Big Belt Mts., 4 mi. S Ft. Logan, 1. Beaverhead County: Donovan, 1. County in question: Yellowstone Park, 1.

Nevada. Humboldt County: Alder Creek, 6000 ft., Pine Forest Mts., 1. Ormsby County: 1/2 mi. S Marlette Lake, 8150 ft., 1. Nye County: South Twin River, Toyabe Mts., 1. White Pine County: Baker Creek (8500 ft., 8675 ft., 11100 ft.), 3.

New Mexico. Taos County: Twining, 10700 ft., 1. Sandoval County: 9 mi. E Cuba, 9000 ft., 1. Santa Fe County: Saddle S of Santa Fe Baldy, 11000 ft., Santa Fe Range, 1.

Oregon. Wasco County: Mill Creek, 20 mi. W Warmsprings, 1. Klamath County: Fort Klamath, 1.

South Dakota. Pennington County: 4 mi. SE Hill City, 5300 ft., 2; Pfander's Ranch, 3 mi. SSE Hill City, 5300 ft., 1; Palmer Gulch, 3 mi. SE Hill City, 5300 ft., 1; Spring Creek, 2 mi. W Oreville, 5500 ft., 1. Custer County: 1/2 mi. E Sylvan Lake, 6250 ft., 1.

Washington. Columbia County: Butte Creek, 1; Stayawhile Spring, 5150 ft., 1.

Wyoming. Crook County: 5 mi. NW Sundance, 5900 ft., 1. Teton County: Whetstone Creek, 2; 1/4 mi. E Moran, 6700 ft., 1. Sublette County: 1/2 mi. NE Pinedale, 7500 ft., 1. Albany County: 30 mi. N and 10 mi. E Laramie, 6560 ft., 1; 26 mi. N and 4-1/2 mi. E Laramie, 6960 ft., 1. Carbon County: 8 mi. N and 19-1/2 mi. E Savery, 8800 ft., 2.

Mustela erminea? angustidens (Brown)

Plates , , and

Putorius cicognanii angustidens Brown, Mem. Amer. Mus. Nat. Hist., 9 (pt 4):181, pl. 17, 1908.

Mustela cicognanii angustidens, Hay, Iowa Geol. Surv. Bull., 23:32, 1914; Hay, Carnegie Inst. Washington, Pub. no. 322A:252, October 15, 1924; Hay, ibid., Pub. no. 390 (vol. 2): 528, 1930; Hall, ibid., Pub. no. 473:111, 112, November 20, 1936.

Type.—Female, adult, skull and lower jaws lacking zygomata, right P2 and incisors, no. 12432, Amer. Mus. Nat. Hist.; from Conard Fissure, four miles west of Willcockson, Newton County, Arkansas; obtained sometime in the period 1903 to 1905 inclusive (see plates , ).

Range.—Known only from the Pleistocene deposit in Conard Fissure, at the type locality in northern Arkansas.

Description.—Skull.—Male (based on nos. 12437, 12441 and 12444): See measurements and plates and ; weight, unknown; basilar length, 38.1 (36.6-39.2); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes less than a third of basilar length; interorbital breadth ordinarily equal to distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably averaging approximately the same as distance between last upper molar and jugular foramen.

Female (based on nos. 11766 and 12435): See measurements and plates 8, 12-14; weight, unknown; basilar length, 34.0 (32.5-35.1); length of tooth-rows more than length of tympanic bulla; breadth of rostrum about equal to (more or less than) 30 per cent of basilar length; interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably less than distance between last upper molar and jugular foramen.

Comparison of the cranial description given above with those of the American races of erminea from the far north will show that many characters are held in common—more than with more southern subspecies of erminea.

Remarks.—The ten specimens studied by the writer fall into two groups of six larger individuals and four smaller. Upon comparing these with each sex of the three species of American Recent weasels, frenata, erminea and rixosa, it is seen that size, and to some degree shape, rule out of consideration both sexes of rixosa and also males of frenata. Thus we are left with females of frenata and males and females of erminea. So far as size is concerned, it can be assumed that the larger specimens are females of frenata and that the smaller are males of erminea. This assumption has in its favor also, the fact that the postglenoidal length of the skull accords with that in Recent specimens. The difference in this regard in Recent animals is that the postglenoidal length of the skull, expressed as a percentage of the total (condylobasal) length of the skull, amounts to:

in frenata in erminea

♂ ordinarily less than 46 ♂ ordinarily more than 46

♀ less than 47 ♀ more than 48

In the fossils the percentage for the larger skulls is 46; for the smaller skulls it is 48.

It may be that the ten fossil skulls are six female frenata and four male erminea but I think not. In the first place a skull of different shape, seemingly of the frenata stock, is known from the deposit and it is almost certain that two subspecies of the same species would not occur at the same place at the same time. It is possible, of course, that parts of the deposits were laid down at times so far apart that a shift in geographic range of two subspecies had occurred. This one skull, seemingly of the frenata stock, is the type of Putorius gracilis Brown (see p. 404) and was regarded as the only known specimen of gracilis. Regardless of the specific identity of this one specimen named gracilis, the chances of obtaining otherwise from a deposit, like that in Conard Fissure, six females of frenata and four males of erminea without a male frenata or a female of erminea coming to light are so slight as strongly to incline me to the view that the six larger specimens are males of the same species to which the 4 smaller specimens belong. By either this interpretation, or the one initially considered (of female frenata and male erminea), the animals from the fissure are at least subspecifically distinct from any American Recent weasel. Furthermore, by this latter interpretation each sex of this weasel, angustidens, is intermediate between the frenata and erminea stocks in the feature of postglenoidal length which feature, at any place where the two Recent species occur together, serves to distinguish one from the other. In the northernmost subspecies of erminea (arctica for example) the postglenoidal length in some males is no longer than in males of frenata. Considering general size, angustidens agrees better with erminea than with frenata and this circumstance has influenced me to place angustidens as a subspecies of erminea.

Today, erminea is not known to occur nearer Conard Fissure than northern Iowa, more than 400 miles to the northward. In comparison with the race there, bangsi, males of angustidens are of approximately the same size but in the shorter distance between the glenoid fossa and anterior margin of the tympanic bulla, and also in the lesser postglenoidal length of the skull, angustidens resembles the northernmost American subspecies of erminea. Females of angustidens differ more from any living weasel than the males do. The females are much larger than those of bangsi, and among living American races of erminea most closely resemble intergrades between arctica and richardsonii which intergrades are found approximately 1700 miles to the north of Conard Fissure. In females, the preorbital part of the skull in M. e. arctica is broader and in M. e. richardsonii narrower than in angustidens. If it seems strange that females of angustidens resemble one subspecies whereas males, in size, resemble another subspecies almost a thousand miles distant, it should be remembered that the degree of sexual dimorphism varies much from one subspecies to another in the Recent animals. An example is furnished by Mustela erminea fallenda and Mustela erminea invicta.

The assemblage of mammals from Conard Fissure includes several species of boreal predilections which, like Mustela erminea, now occur only much farther north than Arkansas. At one time the edge of the sheet of ice was only about 200 miles north of Arkansas. It may be significant that the cranial characters of the female ermine from the Fissure, and qualitative cranial characters of males from there, are most nearly approximated among Recent weasels by those which live along the southern edge of the frozen tundra.

In view of what has been said, the possibility should be considered that the distinctive cranial features of angustidens may be the result of evolutionary change in time as well as of geographic variation resulting from horizontal placement.

Mustela Rixosa (Bangs)

Least Weasel

(Synonymy under subspecies)

Type.—Putorius rixosus Bangs, Proc. Biol. Soc. Washington, 10:21, February 25, 1896.

Range.—From Norway and Switzerland eastward through Siberia and all the way across North America, but unknown from Iceland, Greenland and the Arctic islands west of Greenland; in North America, from the Arctic Life-zone south to Central British Columbia, Montana and into parts of the Upper Austral Life-zone as in the eastern half of the continent.

The southern extension of range in the Appalachians (to North Carolina) is not duplicated in the Rocky Mountains of western North America probably because the region there suitable for rixosa south of Central British Columbia and Montana is occupied by the almost equally small Mustela erminea muricus and related subspecies which seem to fill the ecological role that rixosa plays where it occurs. The small size of females of M. erminea cicognanii in New England may similarly account for the absence of rixosa there.

Characters for ready recognition.—Differs from both Mustela erminea and Mustela frenata by tail a fourth or less of length of head and body and without a black tip (at most a few black hairs at extreme tip in rixosa), and from M. frenata and from M. erminea in regions where it and rixosa occur together, by basilar length of skull less than 32.5 in males and less than 31.0 in females.

Characters of the species.—Size small: Total length less than 250 in males and 225 in females; tail a fourth or less of length of head and body, and without a black pencil and at most with a few black hairs at extreme tip; caudal vertebrae 11 to 16, normally 15 in M. r. rixosa, and 11 in one M. r. eskimo examined; skull with long braincase and short precranial portion, thus essentially same shape as in M. erminea but the largest males of M. rixosa always with a lesser basilar length that even the smallest females of M. erminea or M. frenata of the same geographic area. In fact no specimens of M. frenata have skulls so small as the largest M. rixosa, and skulls of equal size of M. erminea and M. rixosa, for example, M. erminea muricus of Colorado and M. rixosa eskimo of Alaska, differ in that when the skulls are viewed from directly above those of rixosa have the mastoid processes more prominent, or the braincase is higher in relation to its width or both differences together prevail. Stated in another way, comparison of skulls of equal size of rixosa and erminea shows that in the latter the braincase is more nearly flat and is wider above and in front of the mastoid processes; therefore, the greatest breadth of the braincase equals or exceeds the mastoid breadth, whereas the reverse is ordinarily true of rixosa.

Geographic variation.—In the Old World four subspecies are currently recognized (see Allen, 1933:316) and the same number is here recognized in North America. Length of the tail, length of head and body and hind foot, breadth of the rostral part of the skull in relation to its length, and position on the side of the head of the line of demarcation between the dark color of the upper parts and the white underparts, are the features in which geographic variation has been detected. The general impression is that the amount of geographic variation is much less than in Mustela frenata and only slightly less than in Mustela erminea of the same geographic area.

Nomenclature.—It is exceptional for a species which occurs in both the Old- and New-World to take its specific name from New World material, especially if the name was proposed as recently as 1896; most circumboreal species take their names from descriptions of European specimens. Although the least weasel, Mustela rixosa (Bangs) 1896, seems now to be an exception, it may yet turn out that the first available name was based on European material. Zimmermann (1943) shows that the least weasel actually was named on the basis of European material long before 1896 and concludes that the name Putorius minutus Pomel, 1853, based on a specimen from France, is the first available name.

Because Putorius nowadays is relegated to subgeneric rank under the generic name Mustela, we have for consideration the name-combination Mustela minuta (Pomel). Unfortunately for Zimmermann's conclusion, Mustela minuta Pomel is not available because it is preoccupied by Mustela minuta Gervais [= Palaeogale minuta (Gervais), 1848-1852—see Simpson, 1946: 2, 12], a name applied to another species of small mustelid from the Oligocene or lower Miocene deposits of Europe.

Some other early names thought by Zimmermann (1943:290) to have been based on the dwarf weasel of Europe are judged to be nomina nuda and therefore are to be ignored.

The name Mustela minor Nilsson 1820 was thought by Miller (1912:402) to be a renaming, and hence a synonym, of Mustela nivalis Linnaeus. If that is the case the name does not apply to the dwarf weasel. If the name Mustela minor Nilsson was instead based on the dwarf weasel, the name might still be unavailable, depending on rulings on secondary homonyms, because the name might be preoccupied by [Lutra] minor Erxleben 1777 which is a synonym of [Mustela] lutreola Linnaeus 1766. Two names seemingly available for weasels, and in use for them today, which might replace rixosa as the name of the species, are, first, Mustela boccamela Bechstein, 1801, of Sardinia [= Mustela nivalis boccamela of Miller, 1912, 405] and second, Putorius numidicus Pucheran, 1855, of Morocco and Algeria [= Mustela numidica of Allen, G. M., 1939, 183]. As they stand in the current literature, Mustela numidica is a species distinct from the dwarf weasel and the other name, Mustela nivalis boccamela, is an insular subspecies of the mouse weasel. Zimmermann (1943:292), however, implies that M. numidica may belong to the dwarf weasel group when he says "Ob auch iberica Barr.-Ham. als Unterart zu minuta Pom. zu stellen ist, soll hier nicht untersucht werden, ebensowenig die von Cabrera vermutete Zugehörigkeit der grossen nordafrikanischen M. numidica Puch. zur 'iberica-Gruppe'." The answer to this problem requires a taxonomic, rather than a nomenclatural, decision. Whether either M. numidica or M. boccamela are conspecific with the dwarf weasel I cannot at this time ascertain for want of adequate specimens. Because these two names, M. boccamela, and M. numidica, are assigned to kinds of weasels which are currently regarded as specifically distinct from the dwarf weasel, and because all the other names which certainly have been assigned to Old World populations of the dwarf weasel before 1896, so far as I know, are nomina nuda or are preoccupied, the next available name, Mustela rixosa (Bangs, 1896), is here employed.

Remarks.—This species may have a wider geographic range in northeastern North America than is now known. Strong (1930:7) writes that the Naskapi Indians of the interior country of Labrador between Hamilton Inlet and Ungava Bay "have only one name for weasel, mé-tah-kwut, but they say there are three kinds in their territory, a large, an intermediate, and a very small weasel. The latter suggests the least weasel . . . which has not been recorded from northern Labrador."

In the northern part of the range of the species, the winter pelage is white and the summer pelage is brown. In the southern part of the range, that is in the range of the subspecies allegheniensis, the winter pelage is either brown or white and the time of the molt into winter pelage is irregular; each of eleven individuals from Pennsylvania, Michigan and Ohio, taken in December, January, February and March is mostly white but retains some considerable part of the brown pelage of the previous coat on top of the head and usually also along the midline of the entire dorsum. These eleven animals include individuals of each sex. Of each sex, some are adults and some are subadults. Therefore, the delayed or incomplete fall molt, at present, cannot be correlated with either sex or with any particular age. No wild-taken specimens of M. erminea or of M. frenata of the same region show this delayed or incomplete molt.

Possibly this delay or incompleteness of molt is the result of the same cause that lies behind the birth of some M. rixosa in midwinter. As listed below, several litters of young have been found in midwinter. In fact it appears that in the United States, young may be born in every month of the year although, according to existing information, more litters are produced in spring and in winter than in summer and autumn. Many juveniles and young of allegheniensis examined in study collections clearly were born in spring but about as many seem to have been born in midwinter as at any other time (in the light of present knowledge) and this is in contrast to what we know of the two other species of American weasels since their young, so far as known, are born in spring.

One instance is worthy of detailed comment. An adult female, no. 783 Ohio State Museum, taken on January 31, 1931, at Vinton, Meigs County, Ohio, bears the following notation on the attached label "nest plowed out of ground. Very small young escaped—marked like parent. ♀ was nursing." The enlarged mammae on the dried skin substantiate the statement that the female was nursing young. She has a brown mask continuous from one ear through the eye, across the forehead and through the other eye to the opposite ear. On each side of the body a stripe of brown 5 to 10 mm. wide extends from the upper part of the foreleg back to the thigh and base of the tail, uniting there with its opposite and covering the tail. There are a few spots of brown on the shoulders, and rump and one on the middle of the back. Otherwise the specimen is white. One implication of the statement on the label that the young which escaped were marked like the parent (presumably this female parent) is that this female is a partial albino. I am more inclined, however, to the view that there was an unseasonable activity of the particular glands of internal secretion the hormones of which promote embryonic growth and that these glands, or others controlled by them, were in some way responsible for an abnormal progress of molt, or for a reversal of molt in that one molt began before the previous molt had been completed.

Excepting this one specimen, no. 783 from Vinton, Ohio, all of those in transitional pelage indicate that the direction of the molt pattern is the same as in M. frenata and M. erminea. That is to say, the autumnal molt begins on the midventral line and the molt in spring begins on the mid-dorsal line. Furthermore, the normal progress of each molt appears to follow the same pattern that has been described above for Mustela frenata.

A possible explanation of unseasonal molt in the southeastern area of occurrence of the species Mustela rixosa, and a possible explanation of the abnormal molt of the female from Vinton, Ohio, is that the species has only relatively recently invaded the area, and has had insufficient time to adjust the physiology of its molting mechanism to the longer periods of daylight that obtain later in autumn and earlier in spring than farther north. In the other two species of American weasels, the change in length of periods of light, it will be recalled, is known to indirectly control both molt and some changes in the sexual cycle. Wright (1942B:109) has shown that molt in spring precedes by one or two months the birth of young in M. frenata, that the two phenomena are correlated in a way that is statistically significant, and recognizes that progressively longer periods of daylight may be the causal stimulus. The suggestion made above that M. rixosa does not live in New England or in the Rocky Mountains of the western United States because each of the two areas already is inhabited by weasels of almost equally small size, is in line with the idea that rixosa is a recent immigrant to America, or more precisely that rixosa arrived later than erminea.

Natural History.—Habitat and Numbers.—Soper (1946:136) recounts that near the junction of the Antler and Souris rivers, Manitoba, this species occurs "both in the river valleys and on the upper prairies," and later (1948:55), with reference to the Grand Prairie of the Peace River region of Alberta, writes that the least weasel "inhabits both parklands and mixed wood forest environments."

At most times, wherever found, the least weasel is regarded as rare. Not only mammalogists regard it as rare and as a desirable catch, but Indians likewise value it, probably because of its rarity. For example, Osgood (1901:69-70), who caught a female least weasel at Tyonek, Alaska, writes that: "The natives regard the capture of one of these rare animals as a piece of great good fortune. One old Indian who frequently visited our cabin told us that his brother who had caught one when a small boy had in consequence become a 'big chief'; and he assured me that since I had caught one I must surely be destined to become a man of great wealth and power."

Swenk's (1926:313-330) account of the species in Clay County, Nebraska, shows, however, that the animal was far more abundant in 1916 and 1917 than subsequently and inferentially than it was before 1916. Clearest proof of multiannual fluctuation is provided by P. O. Fryklund's (Swanson and Fryklund, 1935:120-126) receipt of weasels from Roseau County, Minnesota. From 1895 to 1932 he had approximately equal opportunity to receive least weasels each year. Those which came to his attention were distributed by years as follows: 1895-1927, 7 individuals in all; winter of 1927-28, 3 individuals; winter of 1928-29, 59 individuals; 1929-1930, 84 individuals; 1930-1935, 3 individuals. "These records indicate a very definite increase in the abundance of least weasels in the Roseau region [in] the two years from the autumn of 1928 to the spring of 1930. Mr. Fryklund has handled 166 least weasels in his 40 years in Roseau County, and of these, 143 were taken in the two years mentioned."

The maximum home range of the least weasel is two acres and a weasel seldom travels farther than ten rods from its burrow according to Polderboer (1942:146) who, in the period December 20, 1939, to January 2, 1940, studied four least weasels and one long-tailed weasel on a 144 acre farm in Butler County, Iowa.

Behavior

Of the voice, Llewellyn (1942:441) records that his captive specimen taken in Virginia uttered a shrill shriek when seizing prey or when teased. When excessively annoyed the weasel also emitted musk.

The sense of smell is used in hunting as was witnessed by George L. Fordyce; he observed a least weasel following the scent of a Peromyscus and saw the least weasel overtake and kill the mouse (Seton, 1929 (2):637).

At a nest in a clover stack, in Manitoba, Criddle (1947:69), on December 27, 1946, found the least weasel "to have been rather remiss in its sanitary habits as its pile of dung was almost, or quite, touching the nest and only just to the side of its entrance." There were 117 voids.

Enemies

The great-horned owl, barn owl and long-tailed weasel are to be counted as enemies since Nelson (1934:252) found the fur, skull and other fragments of the skeleton of a least weasel in one of 26 pellets of the great-horned owl in Wisconsin; Handley (1949:431) found the skull and other skeletal remains of a least weasel in one of 22 pellets of the barn owl in Virginia; and Polderboer, Kuhn and Hendrickson (1941), in Iowa, found the remains of a least weasel in the den and scats of a Mustela frenata. A domestic cat in Michigan killed a least weasel (Dearborn, 1932B:277).

Food

Mice are killed by the least weasel biting into the back of the head and neck according to Allen (1940:460) who reported upon the growth of five young, from Michigan, that he had in captivity. He further states that a weasel was able to kill a mouse in 30 seconds. One large Microtus introduced into the cage slept with a weasel for several days and ate parts of the mice that the weasel killed but then the weasel killed this mouse! Llewellyn (1942:440-441), in writing of a captive from Virginia, says: "When a live mouse was placed in the cage, the weasel sprang upon it almost instantly. Grasping the mouse by the back of the head, the weasel bit its victim through the skull several times in rapid succession and held on with its sharp teeth. The sound of the teeth piercing the bone was distinctly audible at a distance of several feet. During this interval the weasel hugged the mouse closely with its fore legs and pressed it firmly to its belly through a kicking motion of the hind legs. The hold on the back of the head was not relinquished until the mouse was dead. The killing took only a few seconds. Upon releasing the mouse the weasel usually came to the front of the cage and inspected the observer for an interval of several seconds after which it returned to its prey and began its meal at once. Sometimes the blood would be licked from the wound in the back of the head or perhaps an ear would be chewed a bit and the blood licked off, but never did the weasel 'cut the throat' of its prey and 'suck the blood.'

"The weasel ate the head and brain first, beginning at the back of the head and working forward. Just before reaching the nose the process was reversed and eating then proceeded from the base of the skull toward the tail of the mouse. The tip of the nose, maxilla with teeth, and the tail seemed to be the parts least preferred; they were not eaten when an abundance of food was present. At no time did the weasel place its front feet on the mouse in an attempt to hold it. A second or third mouse was killed immediately upon being placed in the cage even though the first one had not been consumed. The weasel, however, usually returned to the partially eaten mouse and finished it before starting on a new one. Upon completing a meal, especially if the meal had been particularly bloody, the weasel rubbed its chin on the bottom of the cage, scooting along and appearing more snakelike than normal. Whenever I attempted to remove a mouse, or partially eaten one, from the cage, the weasel hung to the mouse tenaciously, and often allowed itself to be lifted up in this manner.

"In the six days that the weasel was kept in captivity it was fed 10 house mice having a total weight of 118 grams. As no food was given on one day, the amount of food eaten is probably slightly below the actual capacity of the animal. Since the weasel weighed only about 32 grams, the average amount of food eaten a day was slightly in excess of one-half the weight of the animal."

Polderboer (1942:146-147) found in three dens, in Iowa, bits of Reithrodontomys (harvest mice) and Peromyscus maniculatus (deer mouse), and in the digestive tract of one least weasel there was a bone fragment and a few hairs of a deer mouse. In the account, given beyond, of a nest, Criddle (1947:69) records the Pennsylvania meadow mouse (Microtus pennsylvanicus drummondi) and the Gapper red-backed vole (Clethrionomys gapperi) as prey at Treesbank, Manitoba. The same author, concerning the same place, earlier (1926:199-200) wrote that in 1922 the meadow mouse, Microtus minor, "went into winter quarters in great numbers and its homes were well stocked with provisions . . . all went well until the middle of February, 1923. Then, within a few days, each was taken possession of by a least weasel (Mustela rixosa) and the inhabitants were quickly destroyed. One dwelling was occupied by one of these weasels for about two weeks during which time I observed that it had dragged several mice over the snow to its temporary home. This residence was examined in April, and in it were discovered six dead Microtus minor, one Evotomys, the head of another, and at least six or eight remnants of small rodents including Microtus drummondi, these last remains being chiefly indicated by the hair-lined nest of the weasel.

"The homes of 27 other vole communities examined at this time were all found to have been entered by weasels, the inhabitants having been killed and partly eaten. Moreover, the weasels had made the homes temporary centers from which they raided other rodent habitations in the vicinity. Thus from being an abundant animal this vole was reduced to insignificance in the course of a few weeks, while all other kinds of mice had suffered severely from the same enemy."

An instance of predation on Peromyscus, revealing some of the methods of capturing prey, is recounted by Seton (1929 (2):636-637) who quotes a letter to him from George L. Fordyce, of Youngstown, Ohio, as follows: "While out in the field this morning (Dec. 26), walking along the bank of a ravine at the edge of our golf course, I saw a Field-mouse run out of the bushes into the rough grass that is just outside of the fair-green of the course. In another instant, what I thought at first to be a white Mouse came out at the same place. The Mouse ran into a wheel track, and disappeared under the grass, coming out about 6 feet from where it went in. The white animal followed through the same course, and when it came out, I saw that it was a small Weasel, very little larger than the Mouse, and that it was following the trail of the Mouse by scent.

"For a time the Mouse ran in circles, and zigzagged about, often . . . within 4 or 5 feet of the Weasel; but the latter seemed so intent on the trail, that it did not notice the Mouse to one side. After a time the latter started toward the open golf course; and when the Weasel reached the point where the trail was straight, it sighted the prey, made a sudden dash forward, and, although 25 feet behind, overtook the Mouse while it was going 3 or 4 feet.

"For a few seconds, they seemed to fight, until the Weasel got the Mouse by the throat, and started for the bushes, dragging the body. When it came to within about three feet of me, I moved a little to see what it would do. It dropped its victim, and ran into the ravine. The Mouse had a drop of bright red blood in the center of its white throat. I waited near by for 15 or 20 minutes, thinking the Weasel might come back, but it did not show up again; even an hour later, the Mouse had not been disturbed."

There are two suggestions, but no proof that I know of, in the literature that the least weasel eats insects. Abbott (1884:27-32—1st ed., 1884) gives considerable information on the food (some insects included) of the "little weasel" which he describes (op. cit.; 27) as having "a little pointed tail of a uniform brown color." Although this suggests Mustela rixosa, Abbott mentions on the next page (page ) that a specimen of the smaller weasel measured six and a half inches from the tip of the snout to the base of the tail and that the tail itself measured two and a fourth inches to the tip of the last caudal vertebra. These measurements indicate that Mustela erminea was involved. Because of the uncertainty as to the species of Mustela involved, Abbott's interesting data on food, nest and behavior are not recorded in the present work. Seton (1929 (2):636) says that of several least weasels brought to D. Nicholson at Morden, Manitoba, most of them decayed so quickly that they could not be saved as specimens. To Seton this indicated that insects were an important part of the food of the weasels.

In summary: Least weasels are known to eat harvest mice, deer mice, meadow mice and red-backed mice; it is suspected that they eat also insects.

Reproduction

Polderboer (1948:296) has taken six specimens in "northeastern Iowa [in] . . . January and December—all males in winter pelage. None of these males showed signs of sexual activity; in all, the testes were retracted and diminutive in size. . . . A male least weasel in brown pelage was taken November 17, 1945, at Marion, Iowa. This specimen had large testes that had descended into the scrotum. The testes, when removed, were about the size of medium-sized garden peas. Microscopic examination of the testes and the vasa deferentia showed mature sperms to be present. . . ."

On July 1, 1917, in Clay County, Nebraska, a nest with four young was found (Swenk, 1926:321). On July 29, 1939, an adult and five young were plowed out of the ground in Allegan County, Michigan; one of the two young males weighed 40.5 grams two days after capture (Allen, 1940:459-460). On August 12, 1932, ten young with the mother, were found in Roseau County, Minnesota (Swanson and Fryklund, 1935:125). September appears to have been the month of birth of a specimen, no. 8472 in the Carnegie Museum, taken on November 24 in Pittsburgh, Pennsylvania. In October, a young least weasel is recorded from Pennsylvania (Winecoff, 1930:313). Early December was the time of birth of a specimen, approximately 10 weeks old, no. 88077, University of Michigan, taken on February 21 in Allegan County. On December 25, 1927, in Washington County, Pennsylvania, "five full-sized, though young . . . animals were caught under the same pile of corn fodder" (Sutton, 1929:253). The first week of January seems to have been the time of birth of a juvenile, no. 88080, University of Michigan, taken in Livingston County, Michigan, on March 27, 1943, since the specimen is approximately seven weeks old. On January 15, 1929, in Washington County, Pennsylvania, four young with the eyes yet unopened were obtained from a nest (Sutton, 1929:254). On January 25, 1928, young, the eyes of which may not yet have been open, were taken from a den in Washington County, Pennsylvania, by Winecoff (1930:313), who records other young having been taken in the same month as well as in February. On March 10, a female from North Portal, Saskatchewan, gave birth to four young (Dunk, 1946:392). On April 18, 1916, four young, half grown, were taken in Nebraska (Swenk, 1926:317). On April 2, 1929, three young were found in Roseau County, Minnesota, according to Swanson and Fryklund (1935:125) who remark that: "The Pennsylvania and Minnesota records show that least weasels may be born any time from July to early February in the northern states." Now, with all of the above records available, it turns out that November, May and June are the only months in which young least weasels have not been reported. Of course some of the young, for which the ages were not specified, were born in preceding months. Even so, the data now available suggests that, in the United States, young least weasels may be born in every month of the year. The number per litter is 3, 4, 4, 4, 5, 5, and 10, yielding an average of 5.

The rate of growth of the young has not been studied enough to allow of judging if it differs significantly from that of other species of the genus. Allen (1940:459-460), however, tells us that of the three young females and two young males captured on July 29, 1939, in Allegan County, Michigan, one male that was killed on July 31, 1939, weighed 40.5 grams. The male remaining alive increased from 46 grams (August 5) to 62.5 grams on September 20, having eaten 63 mice while in captivity. The females in the period of August 5 to September 4 increased in weight as follows: 41 up to 49 grams; 44 to 50 grams; and 47 to 58 grams, having eaten, by September 26, 60, 64 and 65 mice.

Concerning a nest in which young were found, Sutton (1929:254) writes that on January 15, 1929, near Burgettstown, Washington County, Pennsylvania, an animal was seen to enter a small hole in a creek bank. After the observer dug in a distance of approximately six inches an adult, female least weasel was seen and obtained. Back of the animal, the hole, which turned sharply downward, was full of water. The weasel first seen was a female nursing young. A chamber, to the side of the hole, filled with dead grass, comprised a nest containing four young with the eyes yet unopened. Several nests occupied by adult least weasels or by least weasels that were old enough to shift for themselves have been found. Polderboer (1942:145-147) in the winter of 1939-40, on a 144 acre farm in Butler County, Iowa, found four least weasels living, singly, in burrows dug by moles and pocket gophers. The nests therein made by mice were used by the least weasels. Winecoff (1930:312-313) mentions one den in Pennsylvania that contained the remains of only mice, "and not a hint of a feather." Above, in the account of food of the least weasel, Criddle's (1926:199-200) account of the havoc wrought by least weasels among the meadow mice (Microtus ochrogaster minor) has been given. In this account he mentions the fur-lined nests of the weasels that had appropriated the homes of the Microtus. Criddle's (1947:69) later account of a nest at Treesbank, Manitoba, is as follows: "A Nest of the Least Weasel.—When a least weasel finds its way into a locality that has a large number of mice in it, it selects for its home one of their nests that has been made in a well concealed place. This it immediately starts to improve by lining it with hair plucked from its victims before eating them; and as long as sufficient numbers of mice remain in the district the weasel continues adding their hair to the nest, so that the thickness of its walls give one a good idea of the length of time it has been in use. The nest is not only used for sleeping in, as most of the food is consumed in it. Frozen mice are taken in to be thawed out and the weasel carries those it has recently killed in to prevent them getting frozen, or perhaps to have them warm for its next meal.

"On January 27, 1946, my son Percy called my attention to a nest that he had just uncovered in a clover stack that we were using. This nest had originally been made by a Drummond's vole, Microtus pennsylvanicus drummondii, and taken from it by the least weasel, Mustela rixosa, the tracks of which had been noticed about the stack yard since the first snow in early November.

"The nest had evidently been in use for at least three months and the continual additions made to its walls had been so great that they were nearly an inch thick of hair matted together so closely that it appeared to be felt. The hair alone weighed nearly 22 gm., so that with this for protection the weasel must have been warm and comfortable through the severest winter weather.

"In the nest were two red-backed mice, Clethrionomys gapperi, one of which had the base of its skull eaten out. No hair had been removed from either of them, but a Microtus lying in a side tunnel some feet away had the long hair plucked from its back and sides. In and close about the nest were found forty-three front parts of mice skulls which had evidently been discarded because of the sharp teeth in the maxillaries. Seven full stomachs and eleven hind feet of adult Microtus with parts of leg bones were disclosed in, or under, the weasel's bed and a few small bits of skin with hair attached were scattered among the plucked hair of the nest.

"This weasel seems to have been rather remiss in its sanitary habits as its pile of dung was almost, or quite, touching the nest and only just to the side of its entrance. It was composed of 117 voids all of which contained much hair and broken bone.

"Six other mouse nests found in the same stack, or others adjoining it, had been thinly lined with hair. One of these had two mice in it, a red-backed with its brain eaten out and a Microtus with some hair plucked from its neck. Another nest contained the front part of a skull with teeth and the hind feet and tail of a red-back. Besides the mice found in the nests seven others were discovered tucked away in side tunnels. One of these mice had most of the hair plucked from its back. Whether all these mice and nests belonged to the same weasel or not I am unable to say, but it is usual for them to have several nests in the area surrounding the one that is used as their headquarters or home."

Mustela rixosa eskimo (Stone)

Least Weasel

Plates and

Putorius rixosus eskimo Stone, Proc. Acad. Nat. Sci. Philadelphia, 1900:44, March 24, 1900.

Putorius (Gale) vulgaris, Coues, Fur-bearing animals, p. 102, 1877 (part).

Putorius rixosus, Bangs, Proc. Biol. Soc. Washington, 10:21, February 25, 1896 (part); Merriam, N. Amer. Fauna, 11:14, June 30, 1896 (part).

Mustela rixosa eskimo, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Swenk, Journ. Mamm., 7:327, November 23, 1926; Hall, Univ. California Publ. Zoöl., 30:421, March 19, 1929.

Type.—Female, age in question, no. 848 in Acad. Nat. Sci. Philadelphia; Point Barrow, Alaska; July 25, 1898; obtained by E. A. McIlhenny. Type not seen by me.

Range.—Alaska and Yukon Territory. See figure on page .

Characters for ready recognition.—Differs from M. r. pygmaea of eastern Asia in longer tail, averaging 11 rather than 16 per cent of length of head and body, and in study skins reaching only to heel instead of to point between heel and toes; from M. r. rixosa in shorter tail averaging 16 rather than 19 per cent of length of head and body and not extending beyond outstretched hind feet in study skins; white of underparts extending dorsally as a reëntrant angle from upper lip to behind eye, rather than delimited dorsally by a boundary between white and brown color that extends straight across cheeks from upper lip to side of body well below eye and ear; breadth of rostrum measured across lacrimal processes more, instead of less, than 85.5 per cent of orbitonasal length; from M. erminea of same region by basilar length of skull less than 32; tail less than 50 and lacking black pencil.

Description.—Size.—Male: The original describer lists measurements of topotypes as follows: Total length, 204, 230; length of tail, 28, 31; length of hind foot, 20, 22. Allowing 5 per cent for shrinkage, the hind feet of 5 topotypes yield an average measurement of 23 for the hind foot.

Female: Measurements of two topotypes are: Total length, 184, 180; length of tail, 25, 25; length of hind foot, 24, 18. In four other topotypes the hind feet, allowing 5 per cent for shrinkage, yield an average of 21.

Color.—Winter pelage all white, rarely with few white hairs in tip of tail but no black pencil; summer pelage with upper parts about Raw Umber and tone 3 of Chocolate pl. 343 of Oberthür and Dauthenay; underparts white, extending over upper lip, insides of limbs and over all four feet. Line of demarcation between underparts and upper parts extends from upper lip posterodorsally to behind eye down to base of ear, up behind ear for a third or more of its height, and back along side of body. Tail unicolor all around and same color as upper parts. Least width of color of underparts averaging 83 per cent of greatest width of color of upper parts.

Skull.—Based on topotypes; see measurements and plates and ; weight, 0.82 (0.74-0.93) grams in males, and 0.80 and 0.84 in two females; basilar length, 29.5 (27.6-30.1) in males and 27.8 (27.1-28.8) in females; otherwise as described in M. e. richardsonii.

Remarks.—Among the earliest specimens preserved was one by Edward W. Nelson in the course of his explorations of the Upper Yukon, and one in 1874 by L. T. Turner from St. Michaels, Alaska. Bangs, in 1896 (p. 22) mentioned the occurrence of the species in Alaska, but it was not until 1900 (p. 44) that Stone named the subspecies, and then principally on the basis of specimens obtained two years before by E. A. McIlhenny.

The large size, broad skull, light color and short tail are the distinguishing subspecific characters of the race eskimo, and the three characters first mentioned are distinguishing features also of the subspecies of Mustela erminea, namely arctica, which inhabits the same region. Possibly eskimo also will be found on Banks Island and the other Arctic islands between Alaska and Greenland, as is M. e. arctica; at the present time no specimens of Mustela rixosa are known from these islands although some race of rixosa would be expected to occur there.

Animals from southern Alaska average slightly smaller than those from northern Alaska, and this decrease in size toward the south probably represents intergradation with M. r. rixosa. Further evidence of intergradation is furnished by the short tail of the specimen from 15 miles east of Atlin; in other particulars this specimen agrees with the subspecies rixosa to which it is here referred. Nevertheless, the short tail, and color pattern, namely reëntrant angle of white behind the eye, is to be seen in all Alaskan specimens examined in the brown pelage, even in no. 107591, from Tyonek on Cook Inlet, which Osgood (1901:69) and Swenk (1926:323) thought might not differ from the subspecies M. r. rixosa.

Each of four male topotypes, hardly subadult in age, probably of a single litter, is much larger than any other specimen seen from Point Barrow. The basilar length, for example, is 31.9 as against 29.5, and the weight of the skull (with lower jaws) is as much as 1.5 grams, as against 0.93 in the heaviest of the other males. Initial examination of materials from Point Barrow raised the suspicion that two distinct species were represented—rixosa and a larger one possibly allied to M. nivalis of the Old World. Nevertheless, further study almost completely allayed the suspicion because the only difference discernible is one of size, and it is supposed that additional specimens will bridge the gap in size and show that M. r. eskimo at Point Barrow averages larger than the adult specimens now available indicate. The four large males of subadult age are nos. 42814-42816 and 42818 of the American Museum of Natural History.

Of the fourteen adult and subadult skulls examined, two display lesions resulting from infestation of the frontal sinuses by nematode parasites. None of the young skulls show such infestation.

Specimens examined.—Total number, 42 as follows. Arranged alphabetically by Territory and District and unless otherwise indicated in the United States National Museum.

Alaska. Barrow and Point Barrow, 19 (8, 7, 2, 1); Wainwright, 1; Mts. back of Icy Cape, 1; west of Beechey Point, 1; west edge of Colville River Delta, 1; Koyukuk River, 16 mi. above Beetles, 1; upper Yukon, 1; Fort Yukon, 1; Stephens Village, 1; Wales, 1; McDonald Creek, tributary of Salcha Slough, 1; near head of Toklat River, 1; head of Kantishna River, 1; St. Michael, 4 (2); Tyonek [= Tyonek], 1; Bethel, 3; vic. Bristol Bay, 1.

Yukon. La Pierre's House, 1; Klotassin River, tributary of White River, 1.

Mustela rixosa rixosa (Bangs)

Least Weasel

Plates and

Putorius rixosus Bangs, Proc. Biol. Soc. Washington, 10:21, pl. 1, fig. 6, pl. 2, fig. 6, pl. 3, fig. 4, February 25, 1896; Merriam, N. Amer. Fauna, 11:14, pl. 2, figs. 7, 7a, June 30, 1896.

Putorius pusillus, Baird, Mamm. N. Amer., p. 159, 1858.

Putorius (Gale) vulgaris, Coues, Fur-bearing animals, p. 102, 1877.

Mustela rixosa, Thomas, Proc. Zoöl. Soc. London, p. 168, March, 1911.

Mustela rixosa rixosa, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Swenk, Journ. Mamm., 7:327, November 23, 1926.

Type.—Female, adult, skin and skull; no. 642 Bangs Coll. in Mus. Comp. Zoöl.; Osler, Saskatchewan; July 15, 1893; obtained by W. C. Colt; original no. 79 according to describer.

The skull lacks the basioccipital, basisphenoid, and left zygomatic arch. The "crowns" of the lower canines are missing; otherwise the teeth are present and entire. The skin is fairly well made, with soles of hind feet up, in good condition and in summer pelage.

Range.—From northern British Columbia and Great Slave Lake south on the west side of the Rocky Mountains to Ootsa Lake, British Columbia, and on the east side of the Rocky Mountains, south to central Montana, North Dakota and Minnesota; eastward in Canada, entirely north of St. Lawrence River, to Atlantic Ocean. See figure on page .

Characters for ready recognition.—Differs from M. r. eskimo in longer tail averaging 19 rather than 16 per cent of length of head and body and extending beyond outstretched hind feet in study skins, rather than to a point short of tips of toes; boundary between brown upper parts and white underparts extending straight across cheeks from upper lip to side of body well below eye and ear, rather than with reëntrant angle from upper lip carrying white upward to point behind eye, and with breadth of rostrum less, instead of more, than 85.5 per cent of orbitonasal length; from M. r. campestris by smaller size: hind foot less than 25 in males and ordinarily less than 22 in females; in males total length less than 216 and tail averaging less than 34, and in females total length averaging less than 182 and tail averaging less than 29; color said to average darker; from M. r. allegheniensis by three average differences, namely lighter color, longer tympanic bullae and larger size of males; from M. frenata and M. erminea of same region by basilar length of skull less than 32; tail less than 50, and lacking black pencil.

Description.—Size.—Male: Six adults and subadults from Shaunavon, Saskatchewan, yield average and extreme measurements as follows: Total length, 202 (188-208); length of tail, 32.5 (31.5-34.0); length of hind foot, 22.8 (21-24).

Female: One adult and 3 subadults from the same area yield average and extreme measurements as follows: Total length, 172 (162-190.5); length of tail, 27.4 (24-34); length of hind foot, 19.6 (17.5-22).

Color.—Winter pelage all white, rarely brown; as described in M. r. eskimo except that line of demarcation on side of head between upper parts and underparts passes almost straight back without the dorsally directed reëntrant area of white behind the eye and ear; least width of color of underparts averaging 52 per cent of greatest width of color of upper parts.

Skull (Based on those from Shaunavon, Sask.)—See measurements and plates and ; weight, 0.88 (0.70-0.98) grams in males and 0.55 (0.54-0.56) in females; basilar length, 29.5 (28.4-30.4) in males and 26.1 (24.7-27.0) in females; otherwise as described in M. e. richardsonii.

Remarks.—As early as 1858 (p. 159) Baird recognized an individual of this race from Pembina, Minnesota, as pertaining to a distinct species. Although he used for it the specific name pusillus originally proposed by DeKay for a small weasel from the state of New York, Baird wisely noted that the specimen he described "may be different from the New York species. . . ." After preparing this account, Baird included a second specimen, from Fort Steilacoom, Washington Territory, which he thought might be the same, but the differences that he was careful to point out, in the light of later knowledge, show it to be of the species Mustela erminea. Only a few other naturalists followed Baird in distinguishing the least weasel as a separate species until Bangs in 1896 (p. 21) clearly differentiated it and proposed for it the name Putorius rixosus, which continues in use today and applies to the species.

The accumulation at the National Museum of Canada, through the energy of Dr. R. M. Anderson, of a good series of specimens from Saskatchewan in the general vicinity of the type locality allows for the first time an adequate conception of the amount of secondary sexual variation and individual variation and permits recognition of subspecific characters to differentiate between M. r. rixosa and the subspecies eskimo and campestris. In comparison with the subspecies allegheniensis the basis for segregation is less clear and will remain somewhat in doubt until additional adults of allegheniensis from, say, Pennsylvania, become available with accurate external measurements taken in the flesh and especially with complete skulls.

Intergradation with the subspecies eskimo is suggested by the short tail of the specimen from fifteen miles east of Atlin, British Columbia; in other particulars that specimen, a skin-alone, agrees with the subspecies rixosa. Intergradation with campestris is indicated by increased size of some specimens from North Dakota, and is suggested with allegheniensis by the color of specimens from Wisconsin and Illinois. Three specimens from Winona County, in southeastern Minnesota, unfortunately are skulls-alone without external measurements. Also, two of these skulls are of young animals. The one adult, unsexed, is from Crystal Springs. Selected cranial measurements are: basilar length, 28.5; length of tympanic bulla, 10.9. These measurements accord with those of males of the subspecies rixosa to which the specimens from Winona County, therefore, are here assigned. The possibilities have not been excluded, however, that the adult is an unusually large female of the subspecies campestris or a male of allegheniensis that has tympanic bullae longer than average for that subspecies.

Some hesitation is felt in assigning the specimens, 8 in all, from eastern Canada to the subspecies rixosa. The skin-alone from Eagle River and the skin, with part of the skull, from St. Michael Bay, are in transitional pelage and are of no help in appraising subspecific characters. The one adult specimen which does have a complete skull is from an island south of the Comb Hills. This animal in all respects agrees with selected individuals of M. r. rixosa from Saskatchewan, but each of the five other skins in summer pelage has spots of dark brown color on the breast. Only about one specimen in three of rixosa from Saskatchewan is similarly marked. Furthermore, on some of the specimens from eastern Canada the spots are larger than on any of the animals from farther west. The greater frequency of brown spots on the breast, the larger average size of these spots, and the darker average coloration of the upper parts are suggestive of geographic variation, the existence of which has to be proved by additional and more complete specimens from eastern Canada. For the time being, specimens from there are tentatively assigned to the race rixosa.

Of 56 subadult and adult skulls only 3 (1 North Dakota; 1 Calgary, Alberta; and 1 Island S Comb Hills, Queb.) display lesions resulting from infestation of the frontal sinuses by nematode parasites. None of the young skulls shows such infestation.

Specimens examined.—Total number, 87 as follows. Arranged alphabetically by provinces and states and within each from north to south. Unless otherwise indicated, specimens are in the United States National Museum.

Alberta. Miette River, 1; 5 mi. NW Camrose, 1; Camrose, 2 (1, 1); "near Camrose," 2; Forks Blindman and Red Deer rivers, 1; Innisfail, 1; Veteran, 1; Diddsbury [= Didsbury], 1; Calgary, 2 (1, 1); Shepard, 1.

British Columbia. Clarks Ranch, Halfway River, Peace River Dist., 1; 15 mi. E Atlin, 1; Wistaria, P. O., 3 (2, 1); Ootsa Lake, 1.

Labrador. Davis Inlet, 1; 30 mi. upriver and 20 mi. toward Groswater Mts., Eagle River, 1; St. Michael Bay, 1.

Mackenzie. Old Fort Reliance, 1; Fort Resolution, 2; Fort Smith, 1.

Manitoba. Gypsumville, 1; Lake St. Martin Reserve, 1.

Minnesota. Roseau County: Cedarbend, 2; Grimstad, 1; America, 2 (1, 1); Malung, 1; Norland, 1; Falun, 3 (1, 1, 1); Palmville, 1; Spruce, 1; Stokes, 1. No locality more definite than Marshall County, 1. Clay County: Moorhead, 1. Winona County: "near" Whitman, 1; Altura, 1; Crystal Springs, 1.

Montana. Sun River Valley, 1; Wibaux in Wibaux County, 1.

North Dakota. Walsh County: Grafton, 15 (3, 1, 5, 2, 1, 1, 1). McHenry County: 4 and 4-1/2 mi. N Upham, 2. Wells County: 1. Morton County: Mandan, 1.

Ontario. Algoma Dist.: Tatnall, near Oba, 1. Moose Factory, 1.

Quebec. Island S of Comb Hills, James Bay, 1. Saguenay County: Natashkwan, 1.

Saskatchewan. Osler, 1; "near Regina," 1; Dollard, 2; Shaunavon (and "near" and 1 mi. NE), 9; Klintowel P. O. (about 15 mi. N of Eastend), 1; Eastend and "near" Eastend, 2.

Mustela rixosa allegheniensis (Rhoads)

Least Weasel

Plates , and

Putorius allegheniensis Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 1900:751, March 25, 1901.

Putorius rixosus allegheniensis, Cory, Mamm. Illinois and Wisconsin, p. 378, 1912.

Mustela allegheniensis, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912.

Mustela rixosa allegheniensis, Swenk, Journ. Mamm., 7:328, November 23, 1926.

Type.—Probably male adult, skin and skull, no. 6195, Acad. Nat. Sci. Philadelphia; near Beallsville, Washington Co., Pa.; about 1885 or 1886; obtained by Robert Hawkins.

Type not seen by me.

Range.—Wisconsin, northern Illinois, northern Indiana, Michigan, Ohio, Pennsylvania east to Dauphin County and south in the mountains to northwestern North Carolina. See figure on page .

Characters for ready recognition.—Distinguished from M. r. rixosa by three average differences, namely, darker color, shorter tympanic bullae, and smaller size of males; from M. r. campestris in smaller size: hind foot less than 25 in males and less than 22 in females; in males total length less than 216 and tail averaging less than 34, color averaging darker; from M. frenata and M. erminea of same region by basilar length less than 31, tail less than 45, and lacking black pencil.

Description.—Size.—Male: An adult or subadult from Fair Oaks, Pa., a subadult from Finleyville, Pa., and an adult from Huttonsville, W. Va., measure, respectively as follows: Total length, 206, 194, 191 (average 197); length of tail, 37, 32, 28 (32); length of hind foot, 23 in each. An adult from Roanoke, Indiana, weighs 40.6 grams.

Female: Two young from Leasuresville, Pa., and Middle Paxton Twp., Pa., measure, respectively, as follows: Total length, 188, 172; length of tail, 33, 30; length of hind foot, 20.5, 21. An adult from Monroeville, Ohio, weighs 40.5 grams and a young individual from Middle Paxton Twp., Pa., 39.3 grams, and a subadult from Swan Creek Exp. Station, Allegan Co., Mich., weighs 49 grams.

Color.—Winter pelage either all white, or brown as in summer; upper parts about Raw Umber, or tone 2 of Carbo Brown of pl. 342 of Oberthür and Dauthenay. Underparts white at least on thoracic region; approximately three-fourths of specimens with brown rictal spot at angle of mouth or with this area covered by brown upper parts which extend down on each side and meet on the underparts in about one specimen out of three; upper lips and hind feet ordinarily brown; toes of forefeet ordinarily white (see under remarks for details of color pattern). Least width of color of underparts in the specimens in which the dark color of the upper parts does not encircle the body averages 60 per cent of greatest width of color of upper parts, or including all specimens the percentage is 42.

Skull (based on specimens from Pa. listed in table of cranial measurements, which see and plates and ).—Basilar length 29.7 and 28.6 in male and 28.0 in female; weights unavailable; otherwise as described in M. e. richardsonii. The length of the tympanic bullae seems to be actually less, and less in relation to the basilar length, than in other American subspecies of M. rixosa.

Remarks.—Robert Kennicott's mention in 1859 (p. 245) of what seems to be this subspecies is the earliest reference to it that I can identify in the literature. He used the specific name pusillus and it was not until 1900 that Samuel N. Rhoads proposed the name Putorius allegheniensis. Since 1900, several records of occurrence have been published which have made the geographic range of this race better known.

An adequate number of specimens has been gathered only from Ohio and from western Pennsylvania. Many from Ohio are without accurate external measurements taken in the flesh. The majority of the specimens from Pennsylvania owe their preservation to the willingness of local officials, who pay bounties on weasels, to save the skins of Mustela rixosa. These specimens ordinarily comprise the skin with locality but because the feet, external measurements in the flesh, and skulls are unavailable, the material is far from adequate and to give an accurate notion of the usual or average cranial characters of allegheniensis in Pennsylvania, skulls from there are especially desirable.

A smaller percentage of the specimens from Ohio than from Pennsylvania have the brown color of the upper parts meeting on the underparts. Also, more of the specimens from Ohio are lighter colored and this suggests intergradation with the subspecies campestris and rixosa to the westward.

From Pennsylvania 23 animals in brown pelage are available. In 5 there is a rictal spot at the angle of the mouth; in 5 the area is white and in 13 the brown color of the upper parts is continuous over the area in question. Only 2 of 23 have the upper lips white. Eight have the color of the upper parts meeting on the venter thus restricting the white of the underparts to the chin, throat, and pectoral region, and 6 of these have a white area in the inguinal region as well. The toes of the forefeet are white in 3 of 4 animals suitable for examination in this regard and the hind feet are marked with white in 3 of the 8 animals which have the hind feet preserved. Mustela rixosa in Pennsylvania parallels the species Mustela frenata in that in this relatively humid area of the northeastern United States the color of the upper parts is darker and the area of the dark-colored upper parts is increased at the expense of the area of the light-colored underparts. Also Mustela erminea in this same region (range of the subspecies Mustela cicognanii) shows the same tendency to darker color of upper parts and their extension in area at the expense of the area of the light-colored underparts, or was mentioned above.

It is difficult to account for the seeming absence of the species from New England and all that part of Canada and the United States south of the St. Lawrence River and northeastward from Pennsylvania. The size of females of M. erminea cicognanii in that territory is so little more than in rixosa that the latter possibly cannot successfully compete with the erminea stock which may already occupy the ecologic niche to which rixosa is adapted. It will be remembered that in western North America in territory seemingly climatically suitable for rixosa it occurs no farther southward than the line below which M. erminea has become reduced to a size comparable with that of M. rixosa.

Of 41 subadult and adult skulls assigned to this subspecies 24 have obvious lesions in the frontal sinuses evidently resulting from infestation by nematodes. More in detail, none of the specimens from Illinois (3 individuals), Pennsylvania (3 barely subadult), or West Virginia (2) displays lesions. From Wisconsin, Indiana, Virginia and North Carolina there is one specimen each and each specimen displays lesions. From Ohio, 17 of 23 specimens display lesions. From Michigan 3 of 8 specimens display lesions; 2 adults and one subadult have lesions and 5 subadults do not have lesions.

Specimens examined.—Total number, 102 as follows: Arranged alphabetically by states and within each state by counties from north to south. Unless otherwise indicated, specimens are in the United States National Museum.

Indiana. Huntington County: Roanoke, 1. Wells County: Harrison Township, 1.

Illinois. Lake County: Deerfield, 3; no locality more definite than county, 1. Cook County: Northfield, 1; La Grange, 1.

Michigan. Tuscola County: 8 mi. N Caro, 1. Santilac County: Deckerville, 1. Allegan County: Swan Creek Exp. Station, 1; Swan Creek Farm, 1; T. 2N, R. 14W, 1; Allegan, 1. Livingston County: George Reserve, 1; 1/2 mi. N Unadilla, 1. Oakland County: Rochester, 1. Macomb County: Romeo, 1. Washtenaw County: 5 mi. SW Ann Arbor, 1. Branch County: vic. Coldwater, 1.

North Carolina. "near Marshall," 1.

Ohio. Northern part of state, 1. Williams County: Stryker, 1. Lucas County: Monclova, 1. Erie County: Sandusky, 2; marsh near Sandusky, 1; Berlin Heights, 1; no locality more definite than county, 1. Wood County: 10 mi. NE Bowling Green, 1; Bowling Green, 4; 3 mi. E Bowling Green 1; Plain Township, 1; Portage Township, 1. Loraine County: Wellington, 1. Huron County: west of Monroeville, 1. Summit County: Ira, 3. Portage County: Suffield, 1. Hancock County: Vanburen, 1; Findlay, 1; 9 mi. S Findlay, 1; no locality more definite than county, 7 (2, 2, 3). Mahoning County: Ellsworth, 1. Crawford County: "near Crestline," 1. Delaware County: Sunbury, 1; Lewis Center, 1; no locality more definite than county, 1. Licking County: Johnstown, 1. Fairfield County: Baltimore, 1; Violet Township, 1. Meigs [= Gallia?] County: Vinton, 1.

Pennsylvania. Erie County: McKeen Twp. 1. Crawford County: Springboro, 1; Pymatuning Swamp, between Hartstown and Shermansville, Sadsbury Twp., 3. Mercer County: Shenango Twp., 1. Lawrence County: Little Beaver Twp., 1. Butler County: Leasuresville, 1; Clearfield Twp., 1; Valencia, 1. Armstrong County: Ford City, Burrell Twp., 1. Indiana County: Smicksburg, 1; N. Mahoning Twp., 2; White Twp., 1. Allegheny County: South Hills, Pittsburgh, 1; "near Pittsburgh," 1; Fair Oaks, 1. Westmoreland County: Bolivar, 1. Dauphin County: Middle Paxton Twp., 1. Washington County: Finleyville, 1; Rea, 5; Beallsville, 1; Claysville, 1. Green County: Deep Valley, 1; Waynesburg, 1; Jefferson, 1; Cumberland Twp., 1. Fayette County: Acme, 1. Somerset County, 1. Lancaster County, 1.

West Virginia. Randolph County: Huttonsville, 1.

Wisconsin. Sauk County: Sumpter Twp., 1. Dodge County: Beaver Dam, 1. Dane County: Madison, 1; McFarland (= MacFarland), 1.

Mustela rixosa campestris Jackson

Least Weasel

Plates and

Mustela campestris Jackson, Proc. Biol. Soc. Washington, 26:124, May 21, 1913.

Putorius pusillus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880, Omaha.

Mustela rixosa campestris, Swenk, Journ. Mamm., 7:329, Nov. 23, 1926.

Type.—Female, adult, skin and skull; no. 171490, U. S. Nat. Mus., Biol. Surv. Coll.; Beemer, Cuming County, Nebraska; April 18, 1911; obtained by G. Sharp; x catalogue no. 8440.

The skull is unbroken. On the left side, C1 and P2 are missing; the other teeth are present and entire. The skin is excellently made and in a good state of preservation.

Range.—South Dakota, Nebraska and Iowa. See figure on page .

Characters for ready recognition.—Differs from M. r. rixosa and M. r. allegheniensis in larger size: Hind foot more than 25 in males and ordinarily more than 22 in females; in males total length more than 216 and tail averaging more than 34; color possibly slightly paler than in M. r. rixosa and averaging paler than in M. r. allegheniensis; from M. frenata and M. erminea of the same region by basilar length less than 32; tail less than 50, and lacking black pencil.

Description.—Size.—Male: Four adults from Nebraska yield average and extreme measurements as follows: Total length, 231 (225-237); length of tail, 36 (32-39); length of hind foot, 29 (28-31).

Female: Six adults from Nebraska yield average and extreme measurements as follows: Total length, 192 (184-225); length of tail, 35 (28-40); length of hind foot, 23 (20.5-26).

Color.—Winter pelage ordinarily white; as described in M. r. eskimo except possibly paler and certainly with line of demarcation on side of head between upper parts and underparts passing almost straight back without the dorsally directed reëntrant angles of white behind the eye and ear; least width of color of underparts in four specimens from Nebraska averaging 80 (49-89) per cent of greatest width of color of upper parts, but in a fifth animal in summer pelage the brown color of the upper parts encircles the body.

Skull.—See measurements in table and plate ; weight 1.1 grams (male from Brown Co., S. D.); basilar length, 30.7 in male from Clay Co., Neb., and 28.8 in female from same county; otherwise as described in M. e. richardsonii.

Remarks.—In his revisionary treatment of the American races of Mustela rixosa, Myron H. Swenk (1926:313) credits Samuel Aughey with recording this animal, M. r. campestris, from Nebraska, as early as 1880, under the name Putorius pusillus. In 1908, Swenk recorded the animal from the same state under the name rixosus and in 1913 the race campestris was formally named by H. H. T. Jackson.