Subfamily Thecosphærida, Haeckel, 1881, Prodromus, pp. 449, 452

Definition.—Liosphærida with three concentric spherical lattice-shells, which are united by radial beams.

Genus 21. Thecosphæra, Haeckel, 1881, Prodromus, p. 452.

Definition.—Liosphærida with two medullary (intracapsular) shells and one cortical (extracapsular) shell.

The genus Thecosphæra comprises a large number of triple-shelled Sphæroidea, formerly united with Actinomma, but different from this genus in the absence of radial spines. The latticed shell is composed of three concentric spheres, two of which lie within the central capsule (medullary shells), and one outside (cortical shell). This latter is connected with the former by radial beams piercing the wall of the central capsule. From the following Rhodosphæra (with one medullary and two cortical shells) Carposphæra differs also by the distance of the three shells. In the former the distance between the two outer shells is much smaller, in the latter much larger, than the distance between the inner shells.

Subgenus 1. Thecosphærantha, Haeckel.

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

1. Thecosphæra triplodictyon, n. sp.

Cortical shell thin walled, smooth, with regular, hexagonal pores, four times as broad as the bars. Radial proportion of the three spheres = 1 : 2 : 8. Both medullary shells with regular circular pores, twice as broad as the bars, the inner half as broad as the outer. All three shells connected by six thin radial beams, opposite in pairs in the three dimensive axes.

Dimensions.—Diameter of the outer shell 0.2, middle 0.05, inner 0.025; cortical pores 0.012, bars 0.003.

Habitat.—Central Pacific, Station 271, surface.

2. Thecosphæra phænaxonia, n. sp.

Cortical shell thick walled, rough, with regular, circular, hexagonally framed pores, twice as broad as the bars. Radial proportion of the three spheres = 1 : 2 : 6. Both medullary shells with regular hexagonal pores and thin bars. All three shells connected by six prismatic radial beams, opposite in pairs in the three dimensive axes. (Shell similar to Hexacontium sceptrum, Pl. , fig. 1, 1a, but without external spines.)

Dimensions.—Diameter of the outer shell 0.12, middle 0.04, inner 0.02; cortical pores 0.01, bars 0.005.

Habitat.—North Pacific, Station 253, surface.

3. Thecosphæra favosa, n. sp.

Cortical shell thick walled, thorny, with regular, circular, hexagonally framed pores, of the same breadth as the bars. Radial proportion of the three spheres = 1 : 3 : 10. Both medullary shells with regular circular pores, connected with the former by twelve short prismatic, regularly disposed radial beams.

Dimensions.—Diameter of the outer shell 0.2, middle 0.06, inner 0.02; cortical pores and bars 0.008.

Habitat.—Central Pacific, Station 268, surface; also fossil in Barbados.

4. Thecosphæra floribunda, n. sp.

Cortical shell thick walled, smooth, with regular, elegantly six-lobed pores, three times as broad as the bars. Radial proportion of the three spheres = 1 : 2 : 4. Both medullary shells with simple regular circular pores, connected with the former by six dimensive radial beams. (Similar to Hexacontium floridum, Pl. , fig. 4, but without external spines.)

Dimensions.—Diameter of the outer shell 0.12, middle 0.06, inner 0.03; cortical pores 0.01, bars 0.0033.

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

Subgenus 2. Thecosphærella, Haeckel.

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

5. Thecosphæra inermis, Haeckel.

Actinomma inerme, Haeckel, 1862, Monogr. d. Radiol., p. 440, Taf. xxiv. fig. 5.

Haliomma inerme, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 815.

Cortical shell thin walled, rough, with regular circular pores, twice as broad as the bars. Radial proportion of the three spheres and of their circular regular pores = 1 : 2 : 4. All three spheres connected by twelve regularly disposed radial beams.

Dimensions.—Diameter of the outer shell 0.1, middle 0.05, inner 0.025; cortical pores 0.006, bars 0.003.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, at many Stations and at various depths.

6. Thecosphæra æquorea, Haeckel.

Haliomma æquorea, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83; Mikrogeol., 1854, Taf. xxii. fig. 35.

Actinomma æquorea, Haeckel, 1862, Monogr. d. Radiol., p. 443.

Cortical shell thick walled, smooth, with regular circular pores of the same breadth as the bars. Radial proportion of the three spheres and of their regular pores = 1 : 2 : 6 or = 1 : 3 : 9; they are connected by six radial beams, opposite by pairs in the three dimensive axes.

Dimensions.—Diameter of the outer shell 0.08 to 0.12, middle 0.03 to 0.04, inner 0.09 to 0.12; cortical pores and bars about 0.006.

Habitat.—Mediterranean, Corfu, surface; fossil in Greece and Sicily.

7. Thecosphæra medusa, Haeckel.

Haliomma medusa, Ehrenberg, 1838, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 130; Mikrogeol., 1854, Taf. xxii. figs. 33, 34.

Actinomma medusa, Haeckel, 1862, Monogr. d. Radiol., p. 444.

Actinomma medusa, Stöhr, 1880, Palæontogr., Bd. xxvi. p. 90, Taf. ii. fig. 3.

Cortical shell thick walled, rough or thorny, with regular circular pores of the same breadth as the bars. Radial proportion of the three spheres = 1 : 2 : 4 (or 1 : 2.5 : 6); they are connected by four radial beams, crossed by pairs in two diameters, perpendicular one to another.

Dimensions.—Diameter of the outer shell 0.08 to 0.12, middle 0.04 to 0.06, inner 0.02 to 0.025; cortical pores and bars in average 0.005.

Habitat.—Fossil in Tertiary rocks of Barbados and the Mediterranean.

8. Thecosphæra entactinia, n. sp.

Cortical shell thick walled, smooth, with regular circular pores of the same breadth as the bars. Radial proportion of the three spheres = 1 : 3 : 12; they are connected by very numerous (forty to fifty, or more) thin radial beams.

Dimensions.—Diameter of the outer shell 0.24, middle 0.06, inner 0.02; cortical pores and bars 0.008.

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

9. Thecosphæra micropora, n. sp.

Cortical shell thin walled, smooth, with very small and numerous, regular, circular pores, half as broad as the bars. Radial proportion of the three shells = 1 : 2 : 5; they are connected by twenty regularly disposed radial beams.

Dimensions.—Diameter of the outer shell 0.2, middle 0.08, inner 0.04; cortical pores 0.002, bars 0.004.

Habitat.—South Pacific, Station 288, surface.

Subgenus 3. Thecosphærina, Haeckel.

Definition.—Pores of the cortical shell irregular polygonal, of unequal size or dissimilar form.

10. Thecosphæra capillacea, n. sp.

Cortical shell thin walled, smooth, with irregular polygonal pores, three to six times as broad as the bars. Both medullary shells with similar, but smaller, pores. Radial proportion of the three spheres = 1 : 3 : 8; they are connected by very numerous (sixty to eighty or more) thin radial beams. (Similar to Actinomma capillaceum, Pl. , fig. 6, but without external spines.)

Dimensions.—Diameter of the outer shell 0.2, middle 0.075, inner 0.025; cortical pores 0.006 to 0.012, bars 0.002.

Habitat.—North Pacific, Station 250, surface.

11. Thecosphæra diplococcus, n. sp.

Cortical shell thick walled, rough, with large irregular polygonal pores, two to three times as broad as the bars. Both medullary shells with small regular circular pores. Radial proportion of the three spheres = 1 : 2 : 6; they are connected by twenty (?) stout radial beams.

Dimensions.—Diameter of the outer shell 0.12, middle 0.04, inner 0.02; cortical pores 0.008 to 0.012, bars 0.004.

Habitat.—South Atlantic, Station 330, surface.

Subgenus 4. Thecosphæromma, Haeckel.

Definition.—Pores of the cortical shell irregular, roundish, of unequal size or dissimilar form.

12. Thecosphæra dodecactis, n. sp.

Cortical shell thin walled, smooth, with large irregular roundish pores, two to eight times as broad as the bars. Both medullary shells with regular circular pores, twice as broad as the bars. Radial proportion of the three spheres = 1 : 2 : 5; they are connected by twelve regularly disposed stout radial beams.

Dimensions.—Diameter of the outer shell 0.2, middle 0.08, inner 0.04; cortical pores 0.004 to 0.016, bars 0.002.

Habitat.—Central Pacific, Station 263, depth 2650 fathoms.

13. Thecosphæra icosactis, n. sp.

Cortical shell thin walled, with small irregular roundish pores, two to four times as broad as the bars. Both medullary shells with similar but smaller pores. Radial proportion of the three spheres = 1 : 3 : 8; they are connected by twenty thin radial beams.

Dimensions.—Diameter of the outer shell 0.32, middle 0.12, inner 0.04; cortical pores 0.005 to 0.012, bars 0.003.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

14. Thecosphæra maxima, n. sp.

Cortical shell thin walled, with small irregular roundish pores, two to six times as broad as the bars. Both medullary shells with similar, but smaller, pores. Radial proportion of the three spheres = 1 : 3 : 9; they are connected by numerous (forty to sixty or more) thin radial beams.

Dimensions.—Diameter of the outer shell 0.45, middle 0.15, inner 0.05; cortical pores 0.008 to 0.024, bars 0.004.

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

Genus 22. Rhodosphæra, Haeckel, 1881, Prodromus, p. 452.

Definition.—Liosphærida with one medullary (intracapsular) shell and two cortical (extracapsular) shells.

The genus Rhodosphæra differs from the preceding Thecosphæra in the same manner in which, among the Dyosphærida, Liosphæra differs from Carposphæra. The cortical shell is double, composed of two not far distant shells, lying outside the central capsule. The distance between the shells is much smaller than the radius of the inner shell. This is connected by radial beams (piercing the central capsule) with the small central medullary shell.

Subgenus 1. Rhodosphærella, Haeckel.

Definition.—Pores of both cortical shells regular, in each shell all of nearly equal size and form.

1. Rhodosphæra hexagonia, n. sp.

Both cortical shells with the same number of regular hexagonal pores; the inner four times as broad as the bars, and half as broad as the outer pores, which are separated by thread-like bars. Medullary shell only one-fourth as broad as the inner cortical shell, with regular hexagonal pores of half the size. (Differs from the similar Liosphæra hexagonia, Pl. , fig. 3, by the possession of a medullary shell.)

Dimensions.—Diameter of the outer shell 0.2, middle 0.16, inner 0.04; outer pores 0.013, middle 0.008, inner 0.004.

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

2. Rhodosphæra melitomma, n. sp.

Both cortical shells with the same number of regular pores; the inner regular, circular, twice as broad as the bars, with elegant hexagonal frames and six roundish lobes alternating with the six radial spines which arise from the hexagon-corners; these short conical spines are connected at the distal end (at equal distances from the centre) by delicate threads (three from each spine), which form the delicate external shell. Medullary shell one-third as broad as the inner cortical shell, with small, simple, regular circular pores. (If in Carposphæra melitomma, Pl. , fig. 4, the distal ends of the spines became united by a cobweb-like outer shell, this species would be formed.)

Dimensions.—Diameter of the outer shell 0.22, middle 0.18, inner 0.06; outer pores 0.025, middle 0.0125, inner 0.005.

Habitat.—Central Pacific, Station 270, depth 2925 fathoms.

Subgenus 2. Rhodosphæromma, Haeckel.

Definition.—Pores of both cortical shells irregular, in each shell of unequal size or dissimilar form.

3. Rhodosphæra palliata, n. sp.

Both cortical shells with an unequal number of irregular roundish pores; the outer pores somewhat smaller and much more numerous than the inner pores; the bars between the latter are thicker. Medullary shell about one quarter as broad as the inner cortical shell, with regular circular pores.

Dimensions.—Diameter of the outer shell 0.4, middle 0.36, inner 0.08; outer pores on an average 0.008, middle 0.012, inner 0.004.

Habitat.—Fossil in Barbados.

4. Rhodosphæra pentaphylla, n. sp.

Both cortical shells with unequal number of irregular roundish pores; the inner pores large, three to four times as broad as the bars; to each inner pore corresponds a group of five smaller outer pores, like the five petals of a flower. Medullary shell half as broad as the inner cortical shell, with regular circular pores.

Dimensions.—Diameter of the outer shell 0.25, middle 0.2, inner 0.1; outer pores on an average 0.006, middle 0.012, inner 0.004.

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