Shell a regular sphere, covered with numerous bristle-shaped radial spines, irregularly scattered between the pores. In the half meridian of the shell two to four very large circular pores (equal to one-third the radius), and between them numerous very small, point-like pores.

Dimensions.—Diameter of the shell 0.05 to 0.08, of the large pores 0.01, of the small 0.001; length of the spines 0.01 to 0.02.

Habitat.—West Tropical Pacific, Philippine Sea, Station 206, depth 2100 fathoms.

4. Acrosphæra spinosa, Haeckel.

Shell a regular or subregular sphere, covered with numerous, obliquely standing spines, irregularly scattered over the surface. In the half meridian of the shell fifteen to twenty irregular roundish pores of very different form and size, one to four times as broad as their bars. Spines conical, irregularly diverging and curved, their hollow base perforated by several pores, not longer than the diameter of the largest pores.

Dimensions.—Diameter of the shell 0.1 to 0.2, of the pores 0.001 to 0.04; length of the spines 0.01 to 0.02.

Habitat.—Mediterranean, Messina; Canary Islands, Haeckel.

5. Acrosphæra collina, n. sp. (Pl. 8, fig. 2).

Shell quite irregular, polyhedrical, hilly, with a variable number (eight to sixteen) of large conical hill-like prominences; every cone or hill about as high as broad, perforated by the same pores as the shell, on its top bearing a larger irregular roundish pore, and on its edge one single bristle-like spine, not larger than the diameter of this pore, obliquely inserted. In the half meridian of the shell twenty to thirty irregular roundish pores of very different size, one to six times as broad as the bars. A very characteristic species, closely resembling the following Odontosphæra.

Dimensions.—Diameter of the shell 0.15 to 0.25, of the pores 0.005 to 0.02; length of the spines 0.01 to 0.02, height of the hills from which they rise 0.03 to 0.04.

Habitat.—North coast of New Guinea, Station 218, surface.

6. Acrosphæra inflata, n. sp. (Pl. 5, fig. 7).

Shell more or less irregular, polyhedral, hilly, with a variable number (six to twelve) of large pyramidal, hill-like prominences; every hill about as high as broad, on the top a strong conical, radial, or obliquely inserted spine, inflated, with three to six very large polygonal meshes, much larger than the other pores between the hills, which are also polygonal, two to six times as broad as the bars. Ten to fifteen pores on the half meridian.

Dimensions.—Diameter of the shell 0.1 to 0.14, of the largest pores 0.05, of the smallest 0.005; length of the spines 0.02 to 0.03.

Habitat.—North Atlantic, Station 64, surface.

Genus 34. Odontosphæra,^[56] n. gen.

Definition.—Collosphærida with simple shells, the outside of which bears single scattered spines, one single spine on the margin of each larger pore.

The genus Odontosphæra is distinguished from the foregoing Acrosphæra by the peculiar disposition of the spines, which are not scattered on the outside of the shell between the pores, but so disposed that each larger pore is protected by one single spine, obliquely placed over it.

1. Odontosphæra monodon, n. sp. (Pl. 5, fig. 5).

Shell spherical or subspherical, with very small and numerous circular pores, much smaller than the bars. Twelve to fifteen pores on the half meridian of the shell. Between them a variable number of larger roundish apertures (mostly twelve to sixteen) irregularly scattered, one-fourth to one-fifth as broad as the shell radius. On the margin of every larger aperture a single (rarely two or three) sharp conical tooth, about as long as the diameter of the aperture, and obliquely laid over them.

Dimensions.—Diameter of the shell 0.1 to 0.13, of the pores 0.001 to 0.003, of the bars 0.01 to 0.02, of the larger apertures 0.01 to 0.02.

Habitat.—Sunda Archipelago, Station 192, surface.

2. Odontosphæra cyrtodon, n. sp. (Pl. 5, fig. 6).

Shell spherical or subspherical, with numerous roundish pores of very irregular size and distribution, mostly larger than the bars. Ten to twelve pores on the half meridian of the shell. Between them a variable number (mostly six to nine) of large roundish pores, about half as broad as the shell radius, armed on one side of the margin with one single large tooth, about as long as the diameter of the aperture, hook-like, curved, and obliquely laid over them.

Dimensions.—Diameter of the shell 0.12 to 0.14, of the pores 0.01 to 0.02, of the bars 0.003 to 0.006, of the larger apertures 0.03 to 0.04.

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

Genus 35. Chœnicosphæra,^[57] n. gen.

Definition.—Collosphærida with simple shells, armed on the outside with radial spines, forming elegant coronals around the larger pores.

The genus Chœnicosphæra is characterised by the peculiar disposition of its radial spines, which form protective coronals around the larger pores, or even around all pores of the shell.

Subgenus 1. Chœnicosphærula.

Definition.—A coronal of spines around every pore of the shell.

1. Chœnicosphæra murrayana, n. sp. (Pl. 8, fig. 4).

Shell spherical, with large circular or roundish pores of unequal size, two to four times as broad as the bars. Ten to twelve pores in the half meridian of the shell. Margin of every pore with a coronal of six to nine short and acute spines, not longer than the half diameter of the pore. No spines between the pores.

Dimensions.—Diameter of the shell 0.16 to 0.2, of the pores 0.02 to 0.03; length of the spines 0.008 to 0.012.

Habitat.—Færöe Channel (Gulf Stream), common. Expedition of H.M.S. "Triton," John Murray.

2. Chœnicosphæra flosculenta, n. sp.

Shell spherical, with large circular or roundish pores of different size, three to six times as broad as the bars. Six to eight pores in the half meridian of the shell. Margin of every pore somewhat prominent, with a coronal of ten to twenty parallel acute spines of different length, the largest somewhat longer than the diameter of the pore. No spines between the pores.

Dimensions.—Diameter of the shell 0.12 to 0.15, of the pores 0.02 to 0.04; length of the spines 0.02 to 0.05.

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

Subgenus 2. Chœnicosphærium.

Definition.—A coronal of spines only around the larger pores, not around the smaller.

3. Chœnicosphæra nassiterna, n. sp. (Pl. 8, fig. 3).

Shell spherical, with circular or roundish pores of very different size. The smaller pores very numerous, without coronal of spines, roundish, about as broad as the bridges. Twenty to thirty pores in the half meridian of the shell. Between them, irregularly scattered, a small number (eight to twelve) of very large circular pores, one-third to one-half as broad as the radius of the shell, armed with a coronal of six to nine parallel, straight, acute spines, about half as long as the radius of the shell.

Dimensions.—Diameter of the shell 0.1 to 0.13, of the smaller pores 0.002 to 0.004, of the larger armed pores 0.02 to 0.03; length of the spines 0.03 to 0.04.

Habitat.—Philippine Islands, Mindanao, Station 213, depth 2050 fathoms.

4. Chœnicosphæra flammabunda, n. sp. (Pl. 8, fig. 5).

Shell spherical, with circular or roundish pores of very different size. The smaller pores very numerous and unequal, very irregularly scattered, hardly one-fourth to one-half as broad as the bridges between them. Twelve to twenty-four pores in the half meridian of the shell. Between them, irregularly scattered, a variable number (ten to twenty) of very large circular pores, about one-fourth as broad as the radius of the shell. The margin of these large pores is armed with a very irregular coronal of four to twelve unequal, curved acute spines, partly simple, partly branched like a deer-horn, one-fourth to one-half as long as the radius of the shell. Some other small spines irregularly scattered over the shell.

Dimensions.—Diameter of the shell 0.12 to 0.16, of the smaller pores 0.001 to 0.004, of the larger armed pores 0.016 to 0.024; length of the spines 0.02 to 0.04.

Habitat.—Central area of the Tropical Pacific, Stations 266 to 272, depth 2425 to 2925 fathoms.

Genus 36. Siphonosphæra,^[58] J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.

Definition.—Collosphærida with simple shells, the pores of which are prolonged into external simple radial tubuli with solid wall; outer mouth of the tubuli truncated, smooth.

The genus Siphonosphæra is, next to Collosphæra, the most common of all Collosphærida, and rich in different species; all agreeing in the tubular prolongation of the pores, and corresponding therefore to Ethmosphæra among the simple Liosphærida.

Subgenus 1. Holosiphonia, Haeckel.

Definition.—All the pores or apertures of the shell prolonged into tubules.

1. Siphonosphæra pansiphonia, n. sp.

Shell a regular sphere, everywhere occupied by short, regular cylindrical tubes, all of the same size and form. Length of the tubules equal to their breadth and to the intervals between them. Ten to twelve tubules in the half meridian of the shell. This most regular species is nearly allied to Collosphæra regularis, and may be derived from it by tubular prolongation of all the regular pores.

Dimensions.—Diameter of the shell 0.1 to 0.12, length and breadth of the tubules 0.005 to 0.006.

Habitat.—Indian Ocean, Sunda Strait, Rabbe, surface.

2. Siphonosphæra marginata, n. sp.

Shell a regular or subregular sphere, occupied by numerous short cylindrical tubules of different sizes. Six to eight tubules in the half meridian of the shell. Diameter of the tubules about equal to their distance apart, but two to four times as large as their length.

Dimensions.—Diameter of the shell 0.1 to 14; length of the tubules 0.004 to 0.006, breadth of the tubules and the intervals 0.01 to 0.02.

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

3. Siphonosphæra tubulosa, J. Müller (Pl. 6, fig. 4).

Shell subspherical or roundish, somewhat irregular, occupied by a small number (five to ten) of short cylindrical tubules, irregularly scattered at great distances; intervals between the tubules very large, two to four times as broad as the length of the tubules, which is equal to their breadth and about one-fifth or one-sixth of the shell diameter. Only two or three tubules in the half meridian of the shell.

Dimensions.—Diameter of the shell 0.12 to 0.15, length and breadth of the tubules 0.02 to 0.03.

Habitat.—Equatorial zone of the Pacific, Stations 225, 265, 268, surface.

4. Siphonosphæra cyathina, n. sp. (Pl. 6, fig. 10).

Shell a regular sphere, everywhere occupied by short cup-like tubules of somewhat different size. In the half meridian of the shell about ten to twelve tubules, nearly cylindrical, but constricted in the middle. Inner and outer aperture of the tubule of the same size; their diameter equal to their length and distance.

Dimensions.—Diameter of the shell 0.1 to 0.12, length and breadth of the tubules 0.005 to 0.01.

Habitat.—West coast of Tropical Africa, Stations 348 to 352, surface.

5. Siphonosphæra patinaria, n. sp. (Pl. 6, figs. 7, 8).

Shell a regular or subregular sphere, occupied by numerous broad cup-like tubules of very different sizes. In the half meridian of the shell about six to eight tubules, very flat, circular or subcircular, much constricted in the middle. Diameter of the inner aperture larger than that of the middle stricture, smaller than that of the outer aperture of the tubule; outer diameter two to four times as great as their length.

Dimensions.—Diameter of the shell 0.1 to 0.15, of the pores 0.01 to 0.04; length of the tubules 0.01, breadth 0.02 to 0.04.

Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.

6. Siphonosphæra infundibulum, n. sp.

Shell subspherical or irregular rounded, occupied by a small number (six to twelve) of large funnel-like tubules of very different size, scattered irregularly at great distances. Intervals between the tubules larger than their length, which surpasses the radius of the shell. Outer opening of the funnels three to four times as broad as the inner.

Dimensions.—Diameter of the shell 0.15; length of the tubules 0.05 to 0.09.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

7. Siphonosphæra conifera, n. sp. (Pl. 6, fig. 9).

Shell subspherical, everywhere occupied by irregular conical tubules, the length of which nearly reaches the shell radius. Inner aperture of the cones two to three times as large as the outer. Four to five tubules in the half meridian of the shell. Distances between the bases of the cones small and irregular.

Dimensions.—Diameter of the shell 0.06 to 0.08, length of the tubules 0.03 to 0.04; inner aperture of the cones 0.01 to 0.02, outer aperture 0.008 to 0.01.

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

8. Siphonosphæra fragilis, n. sp.

Shell quite irregular roundish or nearly ovate, very thin and fragile, everywhere occupied by irregular, short, and broad cylindrical or conical tubes. Six to ten tubes in the half meridian of the shell. Diameter of the tubules about one-eighth that of the shell, three to four times as large as the length of the tubules, and the distance apart of their bases.

Dimensions.—Diameter of the shell 0.16 to 0.24, of the tubules 0.02 to 0.03; length of the tubules 0.006 to 0.008, distance of them 0.005 to 0.009.

Habitat.—East coast of Australia, Sydney, Faber; Station 165, surface.

Subgenus 2. Merosiphonia, Haeckel.

Definition.—Only part of the shell apertures prolonged in tubules, the others simple.

9. Siphonosphæra socialis, n. sp. (Pl. 6, figs. 1, 2).

Shell a regular or subregular sphere, bearing only a small number (one to four, commonly two to three) of short and broad cylindrical tubules, irregularly scattered. Between them many small circular or subcircular pores of different sizes, double as broad as their bars. Eight to ten pores in the half meridian of the shell. Tubules three to six times as broad as the pores, about as long as broad, now quite cylindrical, now somewhat dilated at the outer opening. (Although the shells and cells of this common species are among the smallest, their colonies are among the largest, often containing more than one hundred social individuals, often enclosed in alveoles.)

Dimensions.—Diameter of the shell 0.04 to 0.05, of the pores 0.002 to 0.004, of the tubules 0.015 to 0.02; length of them about the same.

Habitat.—Tropical and subtropical part of the Eastern Atlantic, Cape Verde Islands, Canaries, very common, Haeckel; Stations 338 to 353, surface.

10. Siphonosphæra polysiphonia, n. sp.

Shell a regular or subregular sphere, bearing twelve to sixteen circular pores in its half meridian. Nearly one half the pores simple, very small; the other half prolonged into short cylindrical tubules, half as long as broad, two to four times as broad as the pores and their intervals. This species is nearly related to the foregoing, which it represents in the western tropical part of the Atlantic, but differs constantly in the double size of the shell and the much larger number of the tubules.

Dimensions.—Diameter of the shell 0.06 to 0.09, of the pores 0.002 to 0.004, of the tubules 0.01 to 0.012; their length 0.006 to 0.008, surface.

Habitat.—Tropical and subtropical part of the Western Atlantic, coast of Brazil, &c., Rabbe.

11. Siphonosphæra macrosiphonia, n. sp.

Shell a regular sphere, with numerous very small pores of equal size and distribution. Twelve to sixteen pores in its half meridian. Bars (between the pores) three to four times as broad as their diameter. Only a small number (two to four) of very long cylindrical tubes, irregularly scattered, nearly as long or somewhat longer than the shell diameter; now quite straight, now somewhat curved. Diameter of the cylinders four to six times as large as that of the pores.

Dimensions.—Diameter of the shell 0.1 to 0.12, of the pores 0.002 to 0.004, of the tubules 0.015 to 0.018; length of the tubules 0.08 to 0.16.

Habitat.—Central Tropical Pacific, Station 266 to 272, surface.

12. Siphonosphæra serpula, n. sp. (Pl. 6, fig. 6).

Shell a regular sphere, with numerous very small pores of equal size and distribution. Eight to ten pores in its half meridian; bars between them three to four times as broad as their diameter. Only a small number (six to eight) of very long and snake-like, contorted, cylindrical tubes, irregularly scattered. The shape of the latter is very much like that of the calcareous tubes of some species of Serpula; they are nearly as long as, or longer than, the shell diameter, and four to six times as broad as the pores.

Dimensions.—Diameter of the shell 0.12 to 0.14, of the pores 0.003 to 0.005, of the tubules 0.02 to 0.022; length of the tubules 0.1 to 0.2.

Habitat.—North Eastern Pacific, Station 252 to 262, Sandwich Islands, Haltermann.

13. Siphonosphæra chonophora, n. sp. (Pl. 6, fig. 5).

Shell a regular or subregular sphere, with numerous very small pores of equal size and distribution, ten to twelve in its half meridian. Bars between the pores four to six times their diameter. Only a small number (two to six) of very large funnel-like tubules, irregularly scattered. The inner half of these tubules is a short cylindrical tube, of the same thickness as the shell, three to four times as broad as the pores; the outer half is an irregular funnel, suddenly expanded, with siliceous walls of the utmost tenuity and fragility, often irregularly folded and contorted, like a decayed flower-calyx, often half as large as the shell.

Dimensions.—Diameter of the shell 0.1 to 0.12, of the pores 0.003 to 0.005, inner half of the tubules 0.015 to 0.02, outer funnel-like half 0.05 to 0.08.

Habitat.—South Pacific, Stations 285 to 295, surface.

14. Siphonosphæra pipetta, n. sp. (Pl. 6, fig. 3).

Shell more or less irregularly roundish or subspherical, occupied in part by very small pores, in part by very large cylindrical tubules, inflated in the middle. Number, form, and size of the tubes very irregular; commonly there are five to ten, half as long or as long as the shell radius; their inner and outer aperture about half as broad as their inflated middle part; three to nine times as broad as the pores. A very irregular and variable species.

Dimensions.—Diameter of the shell 0.1 to 0.15, of the pores 0.001 to 0.005, of the tubules 0.015 to 0.03; length of the tubules 0.03 to 0.08.

Habitat.—North Pacific, Stations 242 to 253, surface.

Genus 37. Mazosphæra,^[59] Ehrenberg, 1860.

Definition.—Collosphærida with simple shells, the pores of which are prolonged into external simple radial tubuli with solid wall; outer mouth of each tubulus armed with a single tooth.

The genus Mazosphæra is intermediate between Siphonosphæra and Odontosphæra, agreeing with the former in the tubular prolongation of the pores, with the latter in the possession of a single large protective tooth on the outer opening.

1. Mazosphæra hippotis, n. sp. (Pl. 5, fig. 8).

Shell spherical, with circular pores of irregular size and distribution, scarcely half as broad as the bars; fifteen to twenty on the half meridian of the shell. Between them, irregularly distributed, a variable number (ten to fifteen) of short cylindrical radial tubules, about twice as long as broad, and half as long as the shell radius. Mouth of the tubuli obliquely truncated, having on one side a strong acute tooth.

Dimensions.—Diameter of the shell 0.11 to 0.12, of the pores 0.002 to 0.004, of the bridges 0.006 to 0.009; length of the tubuli 0.03, breadth of them 0.01 to 0.015.

Habitat.—North Pacific, Station 253, depth 3125 fathoms.

2. Mazosphæra lagotis, n. sp. (Pl. 5, fig. 9).

Shell spherical, with circular pores of irregular size and distribution, about as broad as the bars; twelve to sixteen on the half meridian. Between them, irregularly distributed, a variable number (eight to twelve) of long, cylindrical, curved tubules, three to six times as long as broad, and about as long as the shell radius; their external mouth lateral, obliquely truncated, ovate, having on one side a strong conical tooth.

Dimensions.—Diameter of the shell 0.1 to 0.12, of the pores 0.002 to 0.01; length of the tubuli 0.05 to 0.07.

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

3. Mazosphæra lævis, Ehrenberg.

Shell spherical, with very small pores, scarcely one-fourth as broad as the bars. Fifteen to twenty pores on the half meridian of the shell. Between them, irregularly distributed, a variable number (fifteen to twenty) of short conical tubules, about as long as broad, only one-fifth to one-sixth as long as the shell radius. Mouth of the tubuli truncated, with an obtuse short tooth on one side.

Dimensions.—Diameter of the shell 0.08 to 0.09, of the pores 0.001 to 0.002, of the bridges 0.005 to 0.008; length of the tubuli 0.01 to 0.02, breadth of them the same.

Habitat.—Philippine Islands (depth 3300 fathoms), Ehrenberg; Station 206, depth 2100 fathoms; Station 225, depth 4575 fathoms.

4. Mazosphæra apicata, Ehrenberg.

Shell spherical, without small pores, only with a variable number (ten to twenty) of short conical tubules, twice as long as broad, and half as long as the shell radius. Mouths of the tubuli obliquely truncated, with a strong acute tooth on one side. (This species differs from the two preceding by the want of the small pores between the tubules.)

Dimensions.—Diameter of the shell 0.08 to 0.1, of the tubules 0.01.

Habitat.—Philippine Islands (depth 3300 fathoms), Ehrenberg; north coast of New Guinea, depth 2000 fathoms; Station 217.

Genus 38. Trypanosphæra,^[60] n. gen.

Definition.—Collosphærida with simple shells, the pores of which are prolonged into external simple radial tubuli with solid walls; outer mouth of each tubulus armed with a coronal of spines.

The genus Trypanosphæra is intermediate between Siphonosphæra and Chœnicosphæra agreeing with the former in the tubular prolongation of the pores, with the latter in the possession of a coronal of teeth on their outer opening.

Subgenus 1. Trypanosphærula, Haeckel.

Definition.—All pores of the shell prolonged into short coronated tubules.

1. Trypanosphæra trepanata, n. sp. (Pl. 5, fig. 4).

Shell regular spherical, with regular circular pores of nearly equal size, at unequal distances, one to four times as broad as the bars. Eight to ten pores on the half meridian. All the pores prolonged into short cylindrical tubuli about as long as broad, armed on the external mouth with an elegant coronal of twenty to thirty straight bristle-shaped, parallel teeth.

Dimensions.—Diameter of the shell 0.12 to 0.14, of the pores 0.015 to 0.02; length of the tubuli 0.02.

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

2. Trypanosphæra dentata, n. sp.

Shell regular spherical, with regular circular pores of equal size, but at very different distances. Only three to four pores on the half meridian. All the pores prolonged into irregular curved, cylindrical tubuli, about as long as the shell radius, with a coronal of ten to twelve short conical teeth on the distal end.

Dimensions.—Diameter of the shell 0.08 to 0.09; length of the tubuli 0.04, breadth 0.02.

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

Subgenus 2. Trypanosphærium, Haeckel.

Definition.—Only part of the shell-pores prolonged into coronated tubules.

3. Trypanosphæra coronata, n. sp. (Pl. 5, fig. 3).

Shell regular spherical, with irregular roundish pores of very different sizes. On the half meridian four to six large and twelve to sixteen very small pores. About half of the large pores prolonged into short cylindrical tubuli, the outer mouth of each being armed with an elegant coronal of ten to twenty thin irregular teeth.

Dimensions.—Diameter of the shell 0.1 to 0.12, of the large pores 0.01 to 0.02, of the small pores 0.001; length of the tubuli 0.012.

Habitat.—North Pacific, Station 241, depth 2300 fathoms.

4. Trypanosphæra terebrata, n. sp.

Shell irregular roundish, with unequal, small, roundish pores. Sixteen to twenty pores on the half meridian. Six to eight larger pores are prolonged into curved cylindrical tubuli, about as long as the shell radius, with a coronal of ten to twelve strong conical straight teeth on the distal end.

Dimensions.—Diameter of the shell 0.15, of the pores 0.001 to 0.003; length of the tubuli 0.08, breadth 0.02.

Habitat.—West Tropical Pacific, Station 225, depth 4575 fathoms.

5. Trypanosphæra transformata, n. sp. (Pl. 5, figs. 1, 2).

Shell quite irregular, of very variable, roundish, or polyhedral form, with small irregular roundish pores, two to four times as broad as the bars. Ten to thirty on the half meridian. The different form of the shell depends upon the variable number of tubuli, which arise at irregular distances from the shell; commonly three to four, often also five to six, more rarely one or two. The tubuli are now more conical, now more cylindrical, about as long as the shell radius, at other times scarcely one-half or one-third as long, with a coronal of ten to twenty more or less curved teeth on the narrower distal mouth. All the different forms are to be found in one and the same colony, as shown in fig. 1. This cœnobium, which I observed living in Ceylon, exhibited the same peculiar formation as I figured in Collosphæra huxleyi in my Monograph 1862 (Taf. xxxiv. fig. 1). In the centre of the jelly-sphere lies a large globular alveole, surrounded by numerous small, young central capsules without shell; whilst in the surface lies one layer of older capsules, enclosed in shells. Some of the younger capsules exhibit self-division.

Dimensions.—Diameter of the shells 0.08 to 0.12, pores 0.002 to 0.006; length and breadth of the tubuli 0.03 to 0.05.

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

Genus 39. Caminosphæra,^[61] n. gen.

Definition.—Collosphærida with simple shells, the pores of which are prolonged into external branched radial tubuli with solid wall.

The genus Caminosphæra differs from Siphonosphæra (and from all other Collosphærida) in the ramification of the tubuli, which arise from the pores; the walls of the tubuli are solid, not fenestrated.

1. Caminosphæra furcata, n. sp.

Shell spherical or subspherical, with a variable number (four to eight) of short cylindrical tubes, irregularly scattered, about as long as the radius of the shell. Every tube forked, with two cylindrical branches of the same size as the simple basal part of the tube. Mouth of the branches truncated, not dilated. Pores of the shell between the tubes very small, all of the same size, half as broad as their bars. Fifteen to twenty pores in the half meridian of the shell.

Dimensions.—Diameter of the shell 0.1 to 0.12, of the pores 0.001 to 0.002; length of the tubules 0.05 to 0.06, breadth of them 0.012 to 0.015.

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

2. Caminosphæra elongata, n. sp.

Shell spherical, with a large number (twelve to twenty) of long cylindrical tubes, irregularly formed and scattered, somewhat longer than the diameter of the shell. Every tube forked at the distal end, with two or three short irregular branches of unequal size and form; branches much shorter than the undivided basal part of the tube. Mouth of the branches narrowed, truncated. Pores of the shell between the tubes about half as broad, irregularly roundish or polygonal, two to three times as broad as their bars. Ten to twelve pores in the half meridian of the shell.

Dimensions.—Diameter of the shell 0.05 to 0.07, of the pores 0.006 to 0.009; length of the tubules 0.06 to 0.09, breadth of them 0.015 to 0.02.

Habitat.—Tropical Central Pacific, Station 271, depth 2425 fathoms.

3. Caminosphæra dichotoma, n. sp. (Pl. 7, fig. 2).

Shell spherical, with a variable number (ten to fifteen) of cylindrical tubes, irregularly scattered, about as long as the radius of the shell. Every tube furcated, with two cylindrical branches of the same size as the simple basal part of the tube. Mouth of the branches dilated, funnel-like, twice as broad as the tube; the edges irregularly dentated or lacerated. Pores between the tubes small, one-third to one-sixth as broad as these, half as broad as their bars. Ten to twelve pores in the half meridian of the shell.

Dimensions.—Diameter of the shell 0.12 to 0.14, of the pores 0.003 to 0.005; length of the tubules 0.06 to 0.08, breadth of them 0.02 to 0.03.

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

4. Caminosphæra dendrophora, n. sp. (Pl. 7, fig. 1).

Shell spherical, with a variable number (eight to twelve) of long cylindrical tubes, irregularly branched and scattered, nearly as long as the diameter of the shell. Every tube with two to six (commonly three to four) branches of different sizes. Mouth of the branches dilated, funnel-like; the edges irregularly dentated or lacerated. Pores between the tubes half as broad as these, irregularly roundish, twice as broad as their bars. Ten to twelve pores in the half meridian of the shell.

Dimensions.—Diameter of the shell 0.12 to 0.15, of the pores 0.006 to 0.01; length of the tubules 0.1 to 0.13, breadth of them 0.02 to 0.025.

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

Genus 40. Solenosphæra,^[62] n. gen.

Definition.—Collosphærida with simple shells, the pores of which are prolonged into external simple radial tubuli with fenestrated wall; outer mouth of the tubuli truncated, smooth.

The genus Solenosphæra differs from Siphonosphæra in the fenestration of the external radial tubes. A large number of shells, appertaining to this genus, were already described by Ehrenberg, and disposed in five different genera corresponding to the different numbers of the tubuli:—Disolenia with two tubes, Trisolenia with three tubes, Tetrasolenia with four tubes, Pentasolenia with five tubes, Polysolenia with six or more tubes. All these five genera are without value, as those different numbers of tubes occur frequently intermingled in the individual cells of one and the same colony, wherever the form and structure of the tubes is inherited with sufficient constancy to determine the species.

Subgenus 1. Solenosphactra, Haeckel.

Definition.—Tubuli of the shell cylindrical or nearly cylindrical, the outer and inner apertures nearly of the same size.

1. Solenosphæra variabilis, Haeckel.

Shell quite irregular roundish or polyhedral, with roundish pores of different size. Ten to fifteen pores in the half meridian of the shell, two to three times as broad as the bars. Porous tubuli of the shell in variable number (in one and the same colony), three to nine, mostly four to six; cylindrical or subcylindrical or somewhat conical, two to three times as broad as long, not longer than the half radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius of the shell (or somewhat smaller), about as large as the truncated outer aperture. This species is closely related to Collosphæra polyedra (p. 97), and may be derived from it by a short tube-like prolongation of the larger apertures.

Dimensions.—Diameter of the shell 0.1 to 0.16, of the pores 0.005 to 0.015; length of the tubules 0.02 to 0.03, breadth of them 0.04 to 0.06.

Habitat.—Central area of the Tropical Pacific, Stations 270, 271, 272, depths 2425 to 2925 fathoms.

2. Solenosphæra pandora, n. sp. (Pl. 7, figs. 10, 11).

Shell irregular roundish or subglobular, with roundish pores of different sizes, mostly somewhat broader than the bars. About twelve to sixteen pores on the half meridian of the shell. Porous tubuli of the shell of variable number (in one and the same colony), one to six, mostly three to four; cylindrical or nearly cylindrical, somewhat longer than broad, not longer than the radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius of the shell, and a little smaller than the truncated outer aperture.

Dimensions.—Diameter of the shell 0.07 to 0.1, of the pores 0.003 to 0.006; length of the tubuli 0.03 to 0.05, breadth of them 0.02 to 0.03.

Habitat.—Central area of the Tropical Pacific, Stations 266 to 274, depths 2350 to 2925 fathoms.

3. Solenosphæra megalactis, Haeckel.

Shell irregularly polyhedrical, with very small roundish pores, scarcely half as broad as the bars. Only eight to ten pores on the half meridian of the shell. Porous tubuli of the shell of variable number (in one and the same colony), two to five, mostly three or four; cylindrical, about as long as the radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius of the shell, and quite as broad as the truncated outer aperture.

Dimensions.—Diameter of the shell 0.07 to 0.09, of the pores 0.002 to 0.004, of the bars 0.005 to 0.009; length of the tubuli 0.03 to 0.04, breadth of them 0.02.

Habitat.—Pacific; California, Philippine Sea, Ehrenberg; Stations 256 to 285, depths 310 to 3000 fathoms.

4. Solenosphæra serpentina, n. sp. (Pl. 7, fig. 7).

Shell nearly spherical, with very small circular pores, scarcely one-third or one-fourth as broad as the bars. Only five to seven pores in the half meridian of the shell. Porous tubuli of the shell of variable number (in one and the same colony), two to nine, mostly seven or eight; cylindrical, somewhat curved or contorted, once and a half or twice as long as the diameter of the shell, with few very small and widely scattered pores. Inner and outer aperture of the tubuli have the same diameter, about one-fifth or one-fourth that of the shell. (This species is closely allied to Siphonosphæra serpula, but is distinguished from it by the long tortuous tubuli and the small scarce pores.)

Dimensions.—Diameter of the shell 0.08 to 0.1, of the pores 0.001 to 0.002, of the bars 0.004 to 0.008; length of the tubuli 0.12 to 0.18, breadth of them 0.02 to 0.025.

Habitat.—North-eastern Pacific, between Sandwich Islands and California, Haltermann, surface.

Subgenus 2. Solenosphenia, Haeckel.

Definition.—Tubuli of the shell more or less conical, the inner aperture much larger than the outer aperture.

5. Solenosphæra venosa, Haeckel.