Subfamily Ethmosphærida, Haeckel, 1862, Monogr. d. Radiol., p. 348 ( sensu restricto )

Definition.—Liosphærida with one single spherical lattice-shell; living solitary, not aggregated in colonies.

Genus 15. Cenosphæra, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 237.

Definition.—Liosphærida with one single latticed sphere, with simple shell-pores (not prolonged into free tubuli) and with simple shell-cavity (without internal radial beams).

The genus Cenosphæra is the most simple form of all Sphæroidea, and may be regarded as the common ancestral form of this order. The siliceous latticed shell, in which the central capsule is enclosed, represents a simple regular sphere, with simple cavity. The pores of the shell-wall are simple, not prolonged into radial tubuli (as in Ethmosphæra and Sethosphæra). According to the different form of the pores, the numerous species of this genus can be disposed in four different subgenera. Some species may be easily confounded with isolated shells of the corresponding social Collosphæra; but in this latter the spherical shell-form is commonly more or less irregular, in Cenosphæra quite regular.

Subgenus 1. Phormosphæra, Haeckel, 1881, Prodromus, p. 448.

Definition.—Pores of the shell regular or subregular, hexagonal or circular, with hexagonal frames or lobes; all nearly of equal size and form.

1. Cenosphæra primordialis, n. sp.

Shell very thin walled, smooth. Pores hexagonal, regular, or subregular; twelve to fifteen on the half meridian of the shell; bars between them extremely delicate (only visible when three hundred or four hundred times enlarged). Diameter of the shell nine to ten times that of the meshes. This species is remarkable for the extreme delicacy of the arachnoidal network of the simple spherical shell; it may be regarded as the common ancestral form of all Sphæroidea. The shell equals that of Heliosphæra tenuissima (figured in my Monograph, 1862, pl. ix. fig. 2), but differs from it by the smooth surface and the absence of all spines or thorns. I observed this species living in the Indian Ocean, near Ceylon, in 1882; the spherical diameter of the central capsule is about one-third of that of the shell; the contents of the central capsule are colourless and transparent, except the central dark globular nucleus. The same shells also occur in some mounted preparations of surface organisms from the Challenger.

Dimensions.—Diameter of the shell 0.12, of the pores 0.012.

Habitat.—Indian Ocean, Ceylon, Haeckel; Central Pacific, Stations 266, 271, surface.

2. Cenosphæra inermis, Haeckel.

Heliosphæra inermis, Haeckel, 1862, Monogr. d. Radiol., p. 351, Taf. ix. fig. 1.

Surface of the thin-walled shell smooth. Pores regular, hexagonal, twelve to fifteen times as broad as the bars, seven to nine on the quadrant.

Dimensions.—Diameter of the shell 0.08 to 0.12, pores 0.012 to 0.015, bars 0.001.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.

3. Cenosphæra hexagonalis, n. sp.

Surface of the thick-walled shell smooth. Pores regular, hexagonal, five to six times as broad as the bars, six to eight on the quadrant.

Dimensions.—Diameter of the shell 0.1 to 0.15, pores 0.01 to 0.012, bars 0.002.

Habitat.—Central Pacific, Stations 265 to 274, at various depths.

4. Cenosphæra mellifica, n. sp. (Pl. , fig. 9).

Surface of the thick-walled shell smooth. Pores regular, circular, with thin hexagonal frames, four times as broad as the bars, six to eight on the quadrant.

Dimensions.—Diameter of the shell 0.2, pores 0.12, bars 0.003.

Habitat.—South Pacific, Station 288, surface.

5. Cenosphæra favosa, n. sp. (Pl. , fig. 10).

Surface of the thick-walled shell rough. Pores regular, circular, with thin hexagonal frames, three times as broad as the bars, ten to twelve on the quadrant.

Dimensions.—Diameter of the shell 0.2, pores 0.09, bars 0.003.

Habitat.—North Atlantic, Færöe Channel (Gulf Stream), John Murray, surface.

6. Cenosphæra vesparia, n. sp. (Pl. , fig. 11).

Surface of the thick-walled shell smooth. Pores regular, circular, with thick hexagonal frames, twice as broad as the bars, ten to twelve on the quadrant.

Dimensions.—Diameter of the shell 0.25, pores 0.016, bars 0.008.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms, and surface.

7. Cenosphæra bombus, n. sp.

Shell thick walled, rough. Pores regular, circular, with thin hexagonal frames, of the same breadth as the bars, twenty to twenty-two on the quadrant.

Dimensions.—Diameter of the shell 0.3, pores and bars 0.005.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

8. Cenosphæra melecta, n. sp.

Shell thick walled, papillate. Pores regular, circular, double-edged, with thick hexagonal frames, of the same breadth as the bars; a short conical papilla in the corner of each hexagon; fourteen to sixteen pores on the quadrant.

Dimensions.—Diameter of the shell 0.2, pores and bars 0.008.

Habitat.—Fossil in Barbados.

9. Cenosphæra anthophora, n. sp.

Shell thick walled, papillate. Pores regular, circular, with an elegant six-lobed frame and a coronal of six short papillæ; the latter alternating with the six lobes (quite as in Pl. , fig. 1b). Pores twice as broad as the bars, ten to twelve on the quadrant.

Dimensions.—Diameter of the shell 0.13, pores 0.01, bars 0.005.

Habitat.—Central Pacific, Station 271, surface.

10. Cenosphæra rosetta, n. sp.

Shell thin walled, smooth. Pores regular, circular, with an elegant six-lobed outer opening, without papillæ. Pores of the same breadth as the bars, six to eight on the quadrant.

Dimensions.—Diameter of the shell 0.1, pores and bars 0.006.

Habitat.—South Atlantic, Station 323, depth 1900 fathoms.

Subgenus 2. Circosphæra, Haeckel.

Definition.—Pores of the spherical shell regular or subregular, circular, without hexagonal frames or lobes, all nearly of equal size and form.

11. Cenosphæra porophæna, Ehrenberg.

Cenosphæra porophæna, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 31.

Shell thin walled, smooth. Pores regular, circular, six to eight times as broad as the bars, five to six on the quadrant.

Dimensions.—Diameter of the shell 0.1, pores 0.012, bars 0.002.

Habitat.—Mediterranean (Crete, depth 1100 fathoms; Corfu, surface).

12. Cenosphæra setosa, Ehrenberg.

Cenosphæra setosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vii. fig. 1.

Shell thin walled, covered with very short and numerous bristles. Pores regular, circular, five to six times as broad as the bars, six to eight on the quadrant.

Dimensions.—Diameter of the shell 0.17, pores 0.2, bars 0.03.

Habitat.—West Tropical Pacific, 3300 fathoms; Philippine Sea, Station 200, depth 250 fathoms.

13. Cenosphæra plutonis, Ehrenberg.

Cenosphæra plutonis, Ehrenberg, 1854, Mikrogeol., Taf. xxxv. B, B. iv. fig. 20.

Shell thin walled, covered with short conical papillæ. Pores regular, circular, twice as broad as the bars, eight to nine on the quadrant.

Dimensions.—Diameter of the shell 0.09, pores 0.006, bars 0.003.

Habitat.—North Atlantic, Station 353, depth 2965 fathoms.

14. Cenosphæra proserpinæ, n. sp.

Shell thin walled, smooth. Pores regular, circular, four times as broad as the bars, five to six on the quadrant.

Dimensions.—Diameter of the shell 0.08, pores 0.008, bars 0.002.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

15. Cenosphæra eridani, n. sp.

Shell thin walled, smooth. Pores regular, circular, three times as broad as the bars, eleven to twelve on the quadrant.

Dimensions.—Diameter of the shell 0.16, pores 0.01, bars 0.003.

Habitat.—South Pacific, Station 295, depth 1500 fathoms.

16. Cenosphæra lethe, n. sp.

Shell thick walled, smooth. Pores regular, circular, double-edged, five times as broad as the bars, sixteen to eighteen on the quadrant.

Dimensions.—Diameter of the shell 0.25, pores 0.01, bars 0.002.

Habitat.—North Atlantic, Station 64, depth 2700 fathoms.

17. Cenosphæra elysia, n. sp. (Pl. , fig. 8).

Shell thick walled, rough. Pores regular, circular, double-edged, twice as broad as the bars, twelve to fourteen on the quadrant.

Dimensions.—Diameter of the shell 0.2, pores 0.01, bars 0.005.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

18. Cenosphæra nirwana, n. sp.

Shell thick walled, smooth. Pores regular, circular, twice as broad as the bars, twenty-four to twenty-five on the quadrant.

Dimensions.—Diameter of the shell 0.25, pores 0.004, bars 0.002.

Habitat.—Indian Ocean, Belligemma, Ceylon, surface; Haeckel.

19. Cenosphæra maxima, n. sp.

Shell thick walled, smooth. Pores regular, circular, twice as broad as the bars, thirty to thirty-three on the quadrant.

Dimensions.—Diameter of the shell 0.3 to 0.4, pores 0.012, bars 0.006.

Habitat.—West Tropical Pacific, Station 225, depth 4475; also fossil in Barbados.

20. Cenosphæra compacta, n. sp. (Pl. , fig. 7).

Shell very thick walled, rough (its wall one-fourth to one-third as thick as the radius). Pores subregular, circular, of the same breadth as the bars, seven to eight on the quadrant.

Dimensions.—Diameter of the shell 0.15, pores and bars 0.012.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

Cenosphæra radiata, Zittel, 1876 (L. N. , p. 84, Taf. ii. figs. 7, 8), a fossil Cretaceous species, is closely allied to Cenosphæra compacta.

21. Cenosphæra crassa, n. sp.

Shell very thick walled, rough (its wall nearly half as thick as the radius). Pores tubular, double-edged, regular, circular, ten times as broad as the thin united bars, twelve to fourteen on the quadrant.

Dimensions.—Diameter of the shell 0.14, pores 0.01, bars 0.001.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

22. Cenosphæra solida, n. sp.

Shell very thick walled, covered with innumerable short bristles (its wall one-third as thick as the radius). Pores regular, circular, four times as broad as the bars, tubular, eight to ten on the quadrant.

Dimensions.—Diameter of the shell 0.2, pores 0.02, bars 0.005.

Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.

Subgenus 3. Cyrtidosphæra, Haeckel, 1862, Monogr. d. Radiol., p. 348.

Definition.—Pores of the spherical shell irregularly polygonal, of unequal size or form, sometimes roundish with polygonal frames.

23. Cenosphæra reticulata, Haeckel.

Cyrtidosphæra reticulata, Haeckel, 1862, Monogr. d. Radiol., p. 349, Taf. xi. fig. 2.

Shell very thin walled, smooth. Pores irregular, polygonal, two to eight times as broad as the bars, fifteen to twenty on the quadrant (groups of four to eight smaller meshes are scattered on the surface, and separated by reticular rows of larger meshes).

Dimensions.—Diameter of the shell 0.16, pores 0.004 to 0.016, bars 0.002.

Habitat.—Mediterranean (Messina), surface.

24. Cenosphæra tenerrima, n. sp.

Shell extremely thin walled, smooth, like a cobweb. Pores very irregular and small, polygonal with thread-like bars, thirty to forty on the quadrant.

Dimensions.—Diameter of the shell 0.25, pores 0.002 to 0.008, bars under 0.001.

Habitat.—Central Pacific, Station 271, surface.

25. Cenosphæra polygonalis, n. sp.

Shell thin walled, smooth, with irregular, polygonal pores, three to four times as broad as the bars, eight to ten on the quadrant.

Dimensions.—Diameter of the shell 0.2, pores 0.012 to 0.02, bars 0.005.

Habitat.—North Pacific, Station 236, surface.

26. Cenosphæra papillata, n. sp.

Shell thick walled, covered with short conical papillæ. Pores irregular, polygonal, three to five times as broad as the bars, fourteen to sixteen on the quadrant.

Dimensions.—Diameter of the shell 0.12, pores 0.004 to 0.007, bars 0.0015.

Habitat.—South Atlantic, Station 325, surface.

27. Cenosphæra cristata, n. sp.

Shell thick walled, rough. Pores irregular, roundish, surrounded by polygonal crested frames two to three times as broad as the bars, eight to twelve on the quadrant.

Dimensions.—Diameter of the shell 0.16, pores 0.006 to 0.01, bars 0.003.

Habitat.—North Pacific, Station 254, surface.

28. Cenosphæra perforata, n. sp. (Pl. , fig. 10).

Ceriosphæra perforata, Haeckel, 1881, Prodromus et Atlas, loc. cit.

Shell thick walled, rough. Pores irregular, roundish, surrounded by high polygonal funnel-shaped frames, which are solid in the inner half, perforated by numerous very small pores in the outer half, sieve-shaped. Pores one to three times as broad as the bars, of very different size, four to six on the quadrant.

Dimensions.—Diameter of the shell 0.15, pores 0.01 to 0.02, bars 0.005 to 0.01.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

29. Cenosphæra coronata, n. sp. (Pl. , fig. 11).

Shell thick walled, rough. Pores irregular, roundish, surrounded by high polygonal frames bearing on their sharp crest a series of small papillæ, so that each pore is surrounded by a coronal of such spinules. Pores four to eight times as broad as the bars, four to five on the quadrant.

Dimensions.—Diameter of the shell 0.15, pores 0.01 to 0.03, bars 0.002 to 0.008.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

Subgenus 4. Porosphæra, Haeckel.

Definition.—Pores of the spherical shell irregular, roundish, without polygonal frames, of unequal size or form.

30. Cenosphæra antiqua, Haeckel.

Cenosphæra plutonis, var., Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 25, Taf. iv. figs. 47, 48.

Cenosphæra plutonis, var., Stöhr, 1880, Palæontogr. xxvi. p. 85, Taf. i. fig. 1.

Shell thin walled, smooth. Pores irregular, roundish, two to eight times as broad as the bars, ten to fifteen on the quadrant.

Dimensions.—Diameter of the shell 0.15 to 0.2, pores 0.007 to 0.015, bars 0.002 to 0.008.

Habitat.—Fossil in the Jurassic, Cretaceous, and Tertiary formations; living in the depths of the Atlantic and Pacific; Station 332, depth 2200 fathoms; Station 225, depth 4475 fathoms, &c.

31. Cenosphæra gigantea, n. sp.

Shell thick walled, smooth. Pores irregular, roundish, two to five times as broad as the bars, thirty to forty on the quadrant.

Dimensions.—Diameter of the shell 0.4 to 0.5, pores 0.004 to 0.01, bars 0.002.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms; also fossil in Barbados.

32. Cenosphæra marginata, n. sp.

Shell very thick walled, smooth. Pores irregular, roundish, double-edged, three to eight times as broad as the bars, six to eight on the quadrant.

Dimensions.—Diameter of the shell 0.12, pores 0.01 to 0.03, bars 0.004.

Habitat.—Central Pacific, Station 274, depth 2750 fathoms.

33. Cenosphæra aspera, Stöhr.

Cenosphæra aspera, Stöhr, 1880, Palæontogr. Bd. xxvi. p. 85, Taf. i. fig. 2.

Shell thick walled, rough, covered with short conical papillæ. Pores irregular, roundish, of about the same breadth as the bars, eight to twelve on the quadrant.

Dimensions.—Diameter of the shell 0.17, pores and bars 0.01 to 0.04.

Habitat.—Fossil in Tertiary rocks of Sicily; Grotte, Stöhr.

34. Cenosphæra hirsuta, Ehrenberg.

Cenosphæra hirsuta, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss., Berlin, p. 287, Taf. x. fig. 18.

Shell thin walled, rough, covered with innumerable very short bristles. Pores very irregular, roundish, of about the same breadth as the bars.

Dimensions.—Diameter of the shell 0.11, pores and bars 0.002 to 0.012.

Habitat.—Indian Ocean, Zanzibar, Pullen; depth 2200 fathoms.

Genus 16. Stigmosphæra, Haeckel, n. gen.

Definition.—Liosphærida with one single latticed sphere, with simple shell-pores (not prolonged into free tubuli); in the central point of the spherical shell-cavity are united a number of radial beams, which become forked and inserted into the inner surface of the shell by their distal ends.

The genus Stigmosphæra differs from Cenosphæra (and from all other Monosphærida) by internal radial beams, which are united in the centre of the simple spherical shell; these beams are branched, and the distal ends of the branches inserted on the internal surface of the shell. I have observed only two, nearly identical specimens of this genus, both with regular, hexagonal pores and thin bars; the beams were implanted in the corners of the hexagons. In one specimen the surface was covered with short radial bristles, whilst these in the other specimen were prolonged into radial spines (like Acanthosphæra). Possibly this peculiar genus is derived from Carposphæra, by reduction and loss of a central medullary shell.

Stigmosphæra actinocentra, n. sp.

Shell very thin walled, rough, with regular circular, hexagonally framed pores, six times as broad as the bars, eight to ten on the quadrant; in the corner of each hexagon a small bristle. In the central point of the shell are united about twelve (?) thin and straight radial beams, which are forked, with dichotomous branches; the distal ends of the branches are inserted in the corners of the hexagons on the inside of the shell.

Dimensions.—Diameter of the shell 0.15, pores 0.02, bars 0.003.

Habitat.—Central Pacific, Station 271, surface.

Genus 17. Ethmosphæra, Haeckel, 1862, Monogr. d. Radiol., p. 349.

Definition.—Liosphærida with one single latticed sphere, with simple shell-cavity; with shell-pores which are prolonged on the outside in centrifugal, conical, or cylindrical tubuli.

The genus Ethmosphæra differs from the simple Cenosphæra, its ancestral form, by the peculiar formation of the shell-pores; in all observed species of the genus these are quite regular, of nearly equal size and form; their base in the spherical shell-face is hexagonal, but on the outside prolonged into centrifugal, external, radial tubuli, which are either conical or cylindrical (in the latter case both openings of the tubes being equal, in the former the outer opening being smaller than the inner). The solitary Ethmosphæra corresponds to the social Siphonosphæra; but in the former the formation of the shell and of its tubuli is quite regular, in the latter more or less irregular.

Subgenus 1. Ethmosphærella, Haeckel.

Definition.—Tubuli conical, their outer opening smaller than the inner.

1. Ethmosphæra siphonophora, Haeckel.

Ethmosphæra siphonophora, Haeckel, 1862, Monogr. d. Radiol., p. 350, Taf. xi. fig. 1.

Tubuli conical, their outer opening half as broad as the inner and three times as broad as their height. Five to six pores on the quadrant. Diameter of the outer pores one and a half times as large as their distance from each other.

Dimensions.—Diameter of the shell 0.1, outer pores 0.01, their distance 0.007.

Habitat.—Mediterranean (Messina), surface, Haeckel.

2. Ethmosphæra conosiphonia, n. sp. (Pl. , figs. 5, 5a).

Tubuli conical, their outer opening two thirds as broad as the inner, and scarcely broader than their height. Ten to twelve pores on the quadrant. Diameter of the outer pores twice as large as their distance from each other.

Dimensions.—Diameter of the shell 0.17, outer pores 0.01, their distance 0.005.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

3. Ethmosphæra polysiphonia, n. sp. (Pl. , fig. 6).

Tubuli conical, their outer opening three-fourths as broad as the inner and three times as broad as their height. Sixteen to eighteen pores on the quadrant. Diameter of the outer pores three times as large as their distance apart.

Dimensions.—Diameter of the shell 0.2, outer pores 0.008, their distance 0.003.

Habitat.—West Tropical Pacific, Station 225, depth 4475 fathoms; also fossil in Barbados and in Sicily.

Subgenus 2. Ethmosphæromma, Haeckel.

Definition.—Tubuli cylindrical, their outer opening about as large as the inner.

4. Ethmosphæra stenosiphonia, n. sp.

Tubuli cylindrical, short, quite contiguous, so that their diameter is six times as large as their distance apart, but about equal to their height. Nine to ten pores on the quadrant.

Dimensions.—Diameter of the shell 0.14, outer pores 0.012, their distance 0.002.

Habitat.—Central Pacific, Station 271, surface.

5. Ethmosphæra pachysiphonia, n. sp.

Tubuli cylindrical, twice as long as broad, very thick-walled, and nearly contiguous, so that their diameter is five times as large as their distance apart. The thickness of their wall is equal to their lumen. Twelve to fourteen pores on the quadrant.

Dimensions.—Diameter of the shell 0.16, outer pores 0.01, their distance 0.002.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

6. Ethmosphæra leptosiphonia, n. sp.

Tubuli cylindrical, short, about as long as broad, very thin-walled and fragile, separated by wide distances, which are three times as large as their diameter. Six to seven pores on the quadrant. (Very similar to Siphonosphæra cyathina, Pl. , fig. 10, but quite regular, all tubuli retaining the same size and distance.)

Dimensions.—Diameter of the shell 0.12, outer pores 0.01, their distance 0.03.

Habitat.—North Atlantic, Færöe Channel, John Murray; surface.

7. Ethmosphæra macrosiphonia, n. sp.

Tubuli cylindrical, very elongated, four times as long as broad; their bases separated by distances which are equal to their breadth. Eight to ten tubuli on the quadrant. (The tubes are similar to those of Siphonosphæra serpula, Pl. , fig. 6, but quite regular, straight, not curved, all of the same size and at equal distances apart.)

Dimensions.—Diameter of the shell 0.1, length of the tubes 0.04, breadth 0.01, basal distance 0.01.

Habitat.—Indian Ocean, Cocos Islands, surface, Rabbe.

Genus 18. Sethosphæra, Hæckel, 1881, Prodromus, p. 452 (sensu emendato).

Definition.—Liosphærida with one single latticed sphere, with simple shell-cavity; with shell-pores, which are prolonged on the inside into centripetal, conical, or cylindrical tubuli.

The genus Sethosphæra differs from its ancestral form, Cenosphæra, by the production of internal, centripetal, radial tubuli on the inside of the shell (the contrary of the preceding genus Ethmosphæra). It corresponds therefore to the social Pharyngosphæra; but in the latter the formation of the shell and its tubes is more or less irregular, whilst in the former each regular pore is prolonged into a regular tubule.

1. Sethosphæra entosiphonia, n. sp.

Shell with smooth surface and regular circular pores, separated by hexagonal frames, twice as broad as the bars. Six to eight on the quadrant. Each pore is prolonged on the inside of the shell in a short conical centripetal tube, twice as long as its diameter.

Dimensions.—Diameter of the shell 0.15, outer pores 0.008, bars 0.004, length of the tubuli 0.015.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

2. Sethosphæra entosolenia, n. sp.

Shell with smooth surface and regular circular pores, without hexagonal frames, of about the same breadth as the bars. Ten to twelve on the quadrant. Each pore is prolonged on the inside of the shell into a thin cylindrical centripetal tube, three times as long as its diameter.

Dimensions.—Diameter of the shell 0.2, outer pores and bars 0.006, length of the tubuli 0.02.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.