Chapter XI: Literature and History (11)

Shell thin walled, with irregular, polygonal pores, twice to four times as broad as the bars; six to eight on the radius. Twenty radial main spines, three-sided pyramidal, nearly as long as the diameter of the shell, as broad as a larger mesh; innumerable bristle-shaped by-spines variously distributed on the bars and at the nodal-points of the net; half as long as the radius.

_Dimensions._--Diameter of the shell 0.12, pores 0.006 to 0.012, bars 0.003; length of the main spines 0.1, basal breadth 0.012.

_Habitat._--Equatorial Atlantic, Station 347, surface.

12. _Heliosphæra hyperionis_, n. sp.

Shell thick walled. Pores irregular, roundish, with polygonal frames, three to six times as broad as the bars; twelve to fourteen on the radius. Thirty to forty main spines, angular, pyramidal, scarcely as long as the radius and twice as long as the numerous bristle-shaped by-spines.

_Dimensions._--Diameter of the shell 0.24, pores 0.006 to 0.012, bars 0.002; length of the main spines 0.1, basal breadth 0.012.

_Habitat._--North Pacific, Station 256, surface.

13. _Heliosphæra elector_, n. sp.

Shell thick walled, with irregular, roundish pores, twice to three times as broad as the bars; eight to ten on the radius. Twenty main spines, three-sided pyramidal, somewhat longer than the radius and four times as long as the short bristle-shaped by-spines.

{221}_Dimensions._--Diameter of the shell 0.12, pores 0.005 to 0.01, bars 0.003; length of the main spines 0.08, basal breadth 0.01.

_Habitat._--South Atlantic, Station 325, surface.

14. _Heliosphæra solaris_, n. sp.

Shell thick walled, with irregular, roundish pores, about the same breadth as the bars; six to eight on the radius. Fifty to eighty main spines, conical, as long as the radius; by-spines very numerous, also conical, but only as large as one pore.

_Dimensions._--Diameter of the shell 0.15, pores and bars 0.006 to 0.008; length of the main spines 0.08, basal breadth 0.012.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

Genus 90. _Conosphæra_,[124] Haeckel, 1881, Prodromus, p. 451.

_Definition._--#Astrosphærida# with one simple latticed sphere, covered with radial spines having the form of hollow cones with porous walls.

The genus _Conosphæra_ differs from _Acanthosphæra_ in the peculiar formation of the radial spines, which are not simple solid sticks, but hollow cones with porous walls, as immediate elevations of the hollow sphere.

1. _Conosphæra platyconus_, n. sp.

Pores of the shell regular, circular, twice as broad as the bars; ten to twelve on the radius. Conical spines about sixty, regular, broader than they are high, with six to nine pores in the wall.

_Dimensions._--Diameter of the shell 0.16, pores 0.008, bars 0.004; length of the spines 0.012, basal breadth 0.024.

_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.

2. _Conosphæra orthoconus_, n. sp. (Pl. 12, fig. 2).

Pores of the shell irregular, roundish, twice to three times as broad as the bars; fourteen to sixteen on the radius. Conical spines about forty, regular, higher than they are broad, as long as the radius, with sixteen to twenty pores in the wall.

_Dimensions._--Diameter of the shell 0.2, pores 0.008 to 0.012, bars 0.004; length of the spines 0.05, basal breadth 0.03.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

{222}3. _Conosphæra plagioconus_, n. sp. (Pl. 12, fig. 4).

Pores of the shell irregular, polygonal, twice to five times as broad as the bars; twenty to twenty-four on the radius. Conical spines about eighty, irregularly formed and scattered, with oblique (not radial) axes; about as high as broad, with eight to twelve pores in the wall.

_Dimensions._--Diameter of the shell 0.25, pores 0.005 to 0.015, bars 0.003; length of the spines 0.02, basal breadth 0.02.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

Genus 91. _Coscinomma_,[125] n. gen.

_Definition._--#Astrosphærida# with one simple lattice-sphere, covered with simple radial spines; the pores between them prolonged into hollow, conical, or cylindrical tubuli.

The genus _Coscinomma_ exhibits among the Astrosphærida the same peculiar formation that distinguishes _Ethmosphæra_ and _Sethosphæra_ among the Liosphærida; each pore of the simple shell is prolonged into a short conical or cylindrical tubulus, as a rule either on the outside or on the inside of the shell, but sometimes on both sides.

Subgenus 1. _Coscinommarium_, Haeckel.

_Definition._--Pores prolonged into short tubes both on the inside as well as the outside of the shell.

1. _Coscinomma amphisiphon_, Haeckel (Pl. 26, figs. 1, 1_a_, 1_b_).

Pores regular, circular, hexagonally framed, twice as broad as the bars, prolonged on the inside as well as on the outside of the shell into a short truncated conical tube; fifteen to eighteen pores on the radius. In each hexagon-corner arises a bristle-shaped radial spine, half as long as the radius.

_Dimensions._--Diameter of the shell 0.22, pores 0.01, bars 0.005; length of the spines 0.1.

_Habitat._--Central Pacific, Station 271, surface.

Subgenus 2. _Coscinommidium_, Haeckel.

_Definition._--Pores prolonged into external tubes on the outside of the shell.

2. _Coscinomma ectosiphon_, n. sp.

Pores regular, circular, hexagonally framed, twice as broad as the bars, prolonged on the outside of the shell into a short truncated conical tube; ten to twelve pores on the radius. In each {223}hexagon-corner arises a short bristle-shaped spine, twice as long as the tube, one-third as long as the radius. (Very similar to _Ethmosphæra conulosa_, Pl. 12, fig. 5, but differs in the possession of radial spines.)

_Dimensions._--Diameter of the shell 0.2, pores 0.012, bars 0.006; length of the spines 0.04, of the tubes 0.02.

_Habitat._--North Pacific, Station 253, surface.

3. _Coscinomma macrosiphon_, n. sp.

Pores regular, circular, without hexagonal frames, of the same breadth as the bars, prolonged on the outside of the shell into a long cylindrical tube, half as long as the radius (eight to nine pores on the radius); between them bristle-shaped, at the base conical, radial spines of double length.

_Dimensions._--Diameter of the shell 0.16, pores and bars 0.008; length of the spines 0.08, of the tubes 0.04.

_Habitat._--Central Pacific, Station 274, surface.

Subgenus 3. _Coscinommonium_, Haeckel.

_Definition._--Pores prolonged into internal tubes on the inside of the shell.

4. _Coscinomma endosiphon_, n. sp.

Pores regular, circular, hexagonally framed, twice as broad as the bars (fourteen to sixteen on the radius), prolonged on the inside of the shell into a short truncated cylindrical tube. In each hexagon-corner arises a thin, bristle-shaped, radial spine with pyramidal base, half as long as the radius, twice as long as the tube.

_Dimensions._--Diameter of the shell 0.25, pores 0.012, bars 0.006; length of the spines 0.066, of the tubes 0.03.

_Habitat._--South Pacific, Station 288, surface.

Genus 92. _Cladococcus_,[126] J. Müller, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 485.

_Definition._--#Astrosphærida# with one simple lattice-sphere, covered with branched radial spines (the stem of the spine never forked).

The genus _Cladococcus_, together with the following _Elaphococcus_, is distinguished from the other _Coscinommida_ by the ramification of the radial spines covering the surface of the simple hollow lattice-sphere. In _Cladococcus_ each spine sends out three or more lateral branches, which are either simple or again ramified; but the stem of the spine itself is not forked, as in _Elaphococcus_.

{224}Subgenus 1. _Cladococcalis_, Haeckel.

_Definition._--Branches of the spines simple, not ramified. Pores regular, all of nearly equal size and similar form.

1. _Cladococcus arborescens_, J. Müller.

_Cladococcus arborescens_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 31, Taf. i. fig. 2.

Pores of the spherical shell regular, hexagonal, three times as broad as the bars; three to four on the radius. Ten to twenty spines, three-sided prismatic, two to three times as long as the shell diameter; towards the distal end each spine with three branches (one lateral simple straight branch on each edge of the spine).

_Dimensions._--Diameter of the shell 0.1, pores 0.012, bars 0.004; length of the spines 0.2 to 0.3, breadth 0.02.

_Habitat._--Mediterranean (Nice); North Atlantic, Canary Islands, surface.

2. _Cladococcus spinifer_, Haeckel.

_Cladococcus spinifer_, Haeckel, 1862, Monogr. d. Radiol., p. 368, Taf.
xiii. fig. 9.

Pores regular, circular, hexagonally framed, three times as broad as the bars; five to six on the radius. Radial spines, arising from all the nodal-points of the network, three-sided, longer than the shell diameter, with six to twelve simple verticillate branches (two to four branches on each edge).

_Dimensions._--Diameter of the shell 0.08, pores 0.01, bars 0.003; length of the spines 0.1, breadth 0.03.

_Habitat._--Mediterranean (Messina), surface.

3. _Cladococcus penicillus_, n. sp.

Pores subregular, hexagonal, twice as broad as the bars; eight to ten on the radius. Sixty to eighty radial spines, three-sided prismatic, pencil-shaped, longer than the shell diameter; each at the distal end with a brush or pencil composed of nine to twenty-one short, simple, curved branches (three to seven on each edge).

_Dimensions._--Diameter of the shell 0.1, pores 0.006, bars 0.003; length of the spines 0.12 to 0.16, breadth 0.006.

_Habitat._--Central Pacific, Station 271, surface.

Subgenus 2. _Cladococcinus_, Haeckel.

_Definition._--Branches of the spines simple, not ramified. Pores irregular, of different size or form.

{225}4. _Cladococcus antarcticus_, n. sp.

Pores irregular, polygonal, twice to four times as broad as the bars; five to six on the radius. Forty to fifty radial spines, angular, curved, of variable size and form, with three to nine irregular, simple, blunt curved branches.

_Dimensions._--Diameter of the shell 0.14, pores 0.01 to 0.02, bars 0.05; length of the spines 0.1 to 0.18, breadth 0.007.

_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.

5. _Cladococcus japonicus_, n. sp.

Pores irregular, roundish, of the same breadth as the bars; six to eight on the radius. Twenty to thirty radial spines, angular, longer than the shell diameter, with thirty to forty simple branches, decreasing in size from the middle part of the spine to the distal end (ten to thirteen branches on each edge).

_Dimensions._--Diameter of the shell 0.12, pores and bars 0.007; length of the spines 0.15 to 0.2, breadth 0.004.

_Habitat._--North Pacific (Japan), Station 240, surface.

6. _Cladococcus quadricuspis_, n. sp.

Pores irregular, roundish, twice to eight times as broad as the bars; eight to ten on the radius. About twenty radial spines, three-sided prismatic, as long as the shell diameter; in the proximal half simple, with smooth edges; in the distal half with three diverging simple branches, half the length of the spine, with dentated edges.

_Dimensions._--Diameter of the shell 0.15, pores 0.004 to 0.016, bars 0.002; length of the spines 0.17, breadth 0.01.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

Subgenus 3. _Cladococcodes_, Haeckel.

_Definition._--Branches of the spines again ramified. Pores regular, of nearly equal size and similar form.

7. _Cladococcus scoparius_, n. sp. (Pl. 27, fig. 2).

Pores regular, circular, three times as broad as the bars; five to six on the radius. Twenty radial spines, broom-shaped, three times as long as the shell diameter; in the proximal half simple, in the distal half branched, with three to nine branches, which are again ramified; spines and their branches with three smooth edges, not dentated.

_Dimensions._--Diameter of the shell 0.055, pores 0.0075, bars 0.0025; length of the spines 0.15, basal thickness 0.007.

_Habitat._--Central Pacific, Station 271, surface.

{226}8. _Cladococcus viminalis_, Haeckel.

_Cladococcus viminalis_, Haeckel, 1862, Monogr. d. Radiol., p. 369, Taf.
xiv. figs. 2, 3.

Pores regular, circular, hexagonally framed, four times as broad as the bars; five to six on the radius. Radial spines, arising from all the nodal-points of the network, twice as long as the shell diameter; in the basal half simple, in the distal half with three to six long, thin, curved branches, which are partly forked; three edges of the spines dentated.

_Dimensions._--Diameter of the shell 0.08, pores 0.01, bars 0.003; length of the radial spines 0.16, basal breadth 0.003.

_Habitat._--Mediterranean (Messina).

9. _Cladococcus bifurcus_, Haeckel.

_Cladococcus bifurcus_, Haeckel, 1862, Monogr. d. Radiol., p. 368, Taf.
xiii. figs. 7, 8.

Pores regular, circular, hexagonally framed, four times as broad as the bars; five to seven on the radius. Radial spines arising from all the nodal-points, three-sided prismatic, with dentated edges, longer than the shell diameter. On each spine six to nine branches, which are for the most part forked, the distal branches only being simple. (May be regarded as a further developmental stage of _Cladococcus spinifer_ and _Cladococcus viminalis_.)

_Dimensions._--Diameter of the shell 0.08, pores 0.01, bars 0.0025; length of the spines 0.1, basal breadth 0.003.

_Habitat._--Mediterranean (Messina), Canary Islands, Azores, surface.

10. _Cladococcus pinetum_, n. sp. (Pl. 27, fig. 1).

Pores regular, circular, polygonally framed, about the same breadth as the bars: two to three on the radius. About twenty radial spines, very large, three to four times as long as the shell diameter, branched like a pine tree, with straight, stout, three-sided prismatic stem; three prominent edges dentated. On each edge five to seven lateral branches, the distal ends of which are simple, the proximal again ramified, with numerous ramules. The figured specimen is a young one, with branches but little developed.

_Dimensions._--Diameter of the shell 0.06, pores and bars 0.008; length of the spines 0.2 to 0.25 breadth 0.01.

_Habitat._--Central Pacific, Station 266 to 274, surface.

Subgenus 4. _Cladococcurus_, Haeckel.

_Definition._--Branches of the spines again ramified. Pores irregular, of different size and form.

11. _Cladococcus abietinus_, n. sp. (Pl. 27, fig. 3).

Pores irregular, roundish, twice to four times as broad as the bars; six to ten on the radius. About twenty radial spines, two to three times as long as the shell diameter, branched like a pine {227}tree, with straight, stout, three-sided pyramidal stem. From the dentated edges arise numerous verticillate branches, the proximal ends of which are thickly ramified. (Differs from the preceding and similar species mainly in the large size and irregular lattice-work of the shell.)

_Dimensions._--Diameter of the shell 0.12 to 0.14, pores 0.006 to 0.012, bars 0.003; length of the spines 0.25 to 0.4, breadth 0.012.

_Habitat._--North Pacific, Station 256, surface.

12. _Cladococcus tricladus_, n. sp.

Pores irregular, polygonal, twice to eight times as broad as the bars; eight to ten on the radius. About twenty radial spines, three-sided prismatic, twice as long as the shell diameter; in the proximal half simple, with smooth edges; in the distal half with three diverging curved branches, which bifurcate two to three times or ramify irregularly. (Closely related to the simpler _Cladococcus quadricuspis_.)

_Dimensions._--Diameter of the shell 0.16, pores 0.04 to 0.016, bars 0.002; length of the spines 0.3, breadth 0.012.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.

13. _Cladococcus stalactites_, n. sp. (Pl. 27, fig. 4).

Pores irregular, roundish, once to five times as broad as the bars; eight to ten on the radius. About twenty radial spines, very stout, longer than the shell diameter, with three wing-like, prominent smooth edges. At the middle, or in the distal half, each spine bears a verticil of three strong, irregularly formed ramified branches.

_Dimensions._--Diameter of the shell 0.14, pores 0.003 to 0.015, bars 0.003; length of the spines 0.16 to 0.2, breadth 0.02.

_Habitat._--West Tropical Pacific, Station 220, depth 1100 fathoms.

14. _Cladococcus dendrites_, n. sp. (Pl. 27, fig. 5).

Pores irregular, roundish, with denticulate margin, twice to four times as broad as the bars; eight to twelve on the radius. Fifty to eighty radial spines, three-sided prismatic, with elegantly denticulated edges; in the proximal two-thirds simple, in the distal third with a bunch of ten to twenty short simple spines (three to seven on each edge).

_Dimensions._--Diameter of the shell 0.16 to 0.2, pores 0.006 to 0.012, bars 0.003; length of the spines 0.2 to 0.3, breadth 0.01.

_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.

Genus 93. _Elaphococcus_,[127] Haeckel, 1881, Prodromus, p. 450.

_Definition._--#Astrosphærida# with one simple lattice-sphere, covered with forked or dichotomously branched radial spines (the stem of the spine always forked).

{228}The genus _Elaphococcus_ differs from the preceding _Cladococcus_ in the mode of ramification of the radial spines. These are forked; and the forked branches are either simple, again forked, or dichotomously ramified.

Subgenus 1. _Elaphococcinus_, Haeckel.

_Definition._--Pores of the shell regular, of nearly equal size and similar form.

1. _Elaphococcus furcatus_, n. sp.

Pores of the spherical shell regular, hexagonal, four times as broad as the bars; four to five on the radius. Radial spines, arising from all the nodal-points of the network, cylindrical, as long as the radius, simply forked at the distal end; both branches half as long as the undivided part.

_Dimensions._--Diameter of the shell 0.08, pores 0.01, bars 0.0025; length of the spines 0.04, breadth 0.004.

_Habitat._--Tropical Atlantic, Station 348, surface.

2. _Elaphococcus cervicornis_, Haeckel.

_Cladococcus cervicornis_, Haeckel, 1862, Monogr. d. Radiol., p. 370,
Taf. xiv. figs. 4-6.

Pores regular, hexagonal, ten to twenty times as broad as the bars; five to seven on the radius. Fifty to ninety radial spines (or more), arising not only from the nodal-points of the network but also from the bars between them. Each spine is cylindrical, longer than the shell diameter, and repeatedly forked (three to six times), having, therefore, numerous (thirty to sixty or more) curved branches. The distal ends of all branches fall in one spherical face.

_Dimensions._--Diameter of the shell 0.07 to 0.09, pores 0.01 to 0.015, bars 0.001 to 0.015; length of the spines 0.1 to 0.15, breadth 0.005.

_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.

3. _Elaphococcus elaphoceras_, n. sp.

Pores regular, circular, hexagonally framed, three to four times as broad as the bars; six to eight on the radius. At each nodal-point of the hexagon arises a short bristle-shaped, simple by-spine. In addition, there arise from the bars thirty to sixty large main spines, longer than the shell diameter, repeatedly forked in the same way as in the preceding species.

_Dimensions._--Diameter of the shell 0.1, pores 0.008, bars 0.002; length of the spines 0.12, breadth 0.002.

_Habitat._--Central Pacific, Station 272. depth 2600 fathoms.

4. _Elaphococcus umbellifer_, n. sp.

Pores regular, circular, three times as broad as the bars; ten to twelve on the radius. Twenty to forty straight cylindrical spines, as long as the shell diameter, having at the distal end a regular {229}umbel composed of nine to twelve curved branches of equal length, which are again ramified and resemble the inflorescence of an umbelliferous plant, the distal ends of all ramules falling in a spherical face.

_Dimensions._--Diameter of the shell 0.12, pores 0.006, bars 0.002; length of the spines 0.14, breadth 0.002.

_Habitat._--South Atlantic, Station 325, surface.

Subgenus 2. _Elaphococculus_, Haeckel.

_Definition._--Pores of the shell irregular, of different size or form.

5. _Elaphococcus dichotomus_, n. sp.

Pores irregular, polygonal, twice to four times as broad as the bars; six to eight on the radius. Thirty to sixty radial spines cylindrical, curved, as long as the shell diameter, simply forked at the distal end; both branches one-third as long as the undivided part.

_Dimensions._--Diameter of the shell 0.15, pores 0.007 to 0.015, bars 0.004; length of the spines 0.2, breadth 0.004.

_Habitat._--Arctic Ocean, Greenland, surface (Koch).

6. _Elaphococcus umbellatus_, n. sp.

Pores irregular, roundish, or polygonal, twice to five times as broad as the bars; six to eight on the radius. Forty to sixty radial spines cylindrical, curved, as long as the shell radius, having at the distal end an irregular umbel, composed of six to twelve short branches, which are irregularly ramified or forked. (Differs from the regular _Elaphococcus umbellifer_ mainly in the irregularity.)

_Dimensions._--Diameter of the shell 0.14, pores 0.007 to 0.015, bars 0.003; length of the spines 0.12, breadth 0.01.

_Habitat._--South-east Pacific (Juan Fernandez), Station 299, surface.

7. _Elaphococcus drymodes_, n. sp.

Pores irregular, roundish, little broader than the bars; ten to twelve on the radius. Eighty to one hundred and twenty (or more) radial spines, cylindrical, three to four times as long as the shell diameter, irregularly forked or repeatedly dichotomous (each spine with forty to sixty forked branches); the distal ends of all branches fall in a spherical plane. (Differs from the regular _Elaphococcus cervicornis_ mainly in the irregularity.)

_Dimensions._--Diameter of the shell 0.1, pores and bars 0.003 to 0.008; length of the spines 0.3 to 0.4, breadth 0.01.

_Habitat._--Arctic Ocean, Iceland (Steenstrup).

{230}Subfamily HALIOMMIDA,[128] Haeckel.

_Diplosphærida_, Haeckel, 1881, Prodromus, pp. 449, 451.

_Definition._--#Astrosphærida# with two concentric spherical lattice-shells, united by radial beams.

Genus 94. _Haliomma_,[129] Ehrenberg, 1838, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 128.

_Definition._--#Astrosphærida# with one medullary (intracapsular) and one cortical (extracapsular) shell, which are connected by radial beams, piercing the central capsule. Shell surface covered with simple radial spines of the same kind.

The genus _Haliomma_, one of the oldest known Radiolarian genera, contained in the catalogue of its discoverer, Ehrenberg, a large number of very different #Sphærellaria#, belonging to at least sixteen different genera. We limit here the conception of the genus to those Haliommida which bear simple radial spines of one kind on the surface of the cortical shell (the latter being separated from the medullary shell by the central capsule).

Subgenus 1. _Haliommantha_, Haeckel.

_Definition._--Pores of the cortical shell regular, of nearly equal size and similar form; spines on the whole surface (commonly one spine at each nodal-point).

1. _Haliomma hexagonium_, n. sp.

Cortical shell four times as broad as the medullary shell, both having very thin thread-like bars, and regular, hexagonal pores (eighteen to twenty on the radius of the outer, five to six on the radius of the inner shell). The two shells connected by twenty thin thread-like radial beams. At each nodal-point of the outer shell arises a bristle-shaped radial spine, half as long as the radius. (Similar to _Heliosoma radians_, Pl. 28, fig. 3, but with all the spines equal.)

_Dimensions._--Diameter of the outer shell 0.2, inner 0.05; pores of the outer 0.015, of the inner 0.01; length of the spines 0.05.

_Habitat._--Equatorial Atlantic, Station 347, surface.

2. _Haliomma arachnium_, n. sp.

Cortical shell three times as broad as the medullary shell; pores of the former regular, hexagonal, with very thin thread-like bars (fourteen to sixteen on the radius); pores of the latter regular, {231}circular, three times as broad as the bars (four to five on the radius). The two shells connected by about forty radial beams. At each nodal-point of the outer shell arises one bristle-shaped radial spine, twice as long as the diameter of one hexagonal mesh.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; pores of the outer 0.012, of the inner 0.006; length of the spines 0.025.

_Habitat._--Central Pacific, Station 266, surface.

3. _Haliomma favosum_, n. sp.

Cortical shell thick walled, three times as broad as the medullary shell, with regular, circular, hexagonally framed pores, twice as broad as the bars; eight to ten on the radius. Medullary shell with simple, circular pores, of the same breadth as the bars. At each nodal-point of the outer shell arises a short triangular spine three times as long as one pore.

_Dimensions._--Diameter of the outer shell 0.12, inner 0.04; pores of the former 0.01, of the latter 0.005; bars 0.005; length of the spines 0.015.

_Habitat._--Central Pacific, Station 271 to 274, surface.

4. _Haliomma regulare_, n. sp.

Cortical shell thin walled, nearly twice as broad as the medullary shell, and connected with it by forty to sixty thin radial beams. Both shells of the same perfectly regular structure, with an identical number of regular, circular pores, which are hexagonally framed, four times as broad as the bars, nine to eleven on the radius. The outer pores are twice as broad as the inner, exactly corresponding pores. Between every three pores of the outer surface (in each corner of the cortical hexagon) arises one short three-sided pyramidal spine, twice as long as the diameter of one pore.

_Dimensions._--Diameter of the outer shell 0.2, of the inner 0.11; pores of the former 0.018, of the latter 0.009; length of the spines 0.04.

_Habitat._--South Atlantic (Tristan da Cunha), Station 332, depth 2200 fathoms.

5. _Haliomma melitomma_, n. sp. (Pl. 20, fig. 4).

_Melitomma formosum_, Haeckel, 1879, Atlas, _loc. cit._

Cortical shell thick walled, two and a half times as broad as the medullary shell, with regular pores of very elegant structure, twice as broad as the bars; eight to ten on the radius. The inner opening of each pore is simple, circular, the outer regular, six-lobed; corresponding to the six lobes are six short conical spines, which arise from the six corners of the regular hexagonal frames separating the pores. Pores of the medullary shell simple, circular, of the same breadth as the bars. The two shells connected only by six radial beams (in three dimensive axes).

_Dimensions._--Diameter of the outer shell 0.17, of the inner 0.07; pores of the former 0.012, of the latter 0.004; length of the spines 0.005 to 0.01.

_Habitat._--Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.

{232}6. _Haliomma lirianthus_, n. sp. (Pl. 28, figs. 1, 1_a_, 1_b_).

Cortical shell thick walled, three times as broad as the medullary shell, with regular, rosette-shaped pores, twice as broad as the bars; eight to ten on the radius. The regular structure of the elegant pores is the same as in the preceding species, but without prominent crested frames (fig. 1_b_). Also the medullary shell (fig. 1_a_) is different, much thinner and smaller, with simple, circular pores, which are three times as broad as the bars. The two shells are connected by numerous (twenty?) radial beams.

_Dimensions._--Diameter of the outer shell 0.15, of the inner 0.05; pores of the former 0.01, of the latter 0.005; length of the spines 0.005 to 0.02.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

7. _Haliomma castanea_, Haeckel.

_Haliomma castanea_, Haeckel, 1862, Monogr. d. Radiol., p. 428, Taf.
xxiv. fig. 4.

Cortical shell thick walled, three times as broad as the medullary shell; pores of both regular, circular, twice as broad as the bars (seven to eight on the radius of the outer, four to five on the radius of the inner shell), the two connected by six to twelve (?) strong radial beams. Radial spines bristle-shaped, with conical bases, twice as long as the diameter of the cortical pores (one spine at the nodal-point between every three pores).

_Dimensions._--Diameter of the outer shell 0.1 to 0.15, inner 0.03 to 0.05; pores of the former 0.005, of the latter 0.003; length of the spines 0.005 to 0.01.

_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.

8. _Haliomma horridum_, Stöhr.

_Haliomma horridum_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 87, Taf. i.
fig. 10.

Cortical shell thick walled, two and a half times as broad as the medullary shell. Pores regular, circular, of the same breadth as the bars; eight to ten on the radius. Radial spines conical, stout, nearly half as long as the radius. (Differs from the closely allied _Haliomma castanea_ in the smaller pores and larger spines.)

_Dimensions._--Diameter of the outer shell 0.14, of the inner 0.06; pores of the former 0.004, of the latter 0.02.

_Habitat._--Fossil in Tertiary rocks of Barbados and Sicily; living in the Atlantic, Station 9, depth 3150 fathoms, and Station 353, depth 2965 fathoms.

9. _Haliomma datura_, n. sp.

Cortical shell thin walled, only one and a half times as broad as the medullary shell, both having regular, circular pores, four to six times as broad as the bars (five to six on the radius of the outer, three to four on the radius of the inner shell), the two connected by numerous (forty to sixty?) thin, short, radial beams. Radial spines conical, twice as long as the diameter of one cortical pore, arising from all the nodal-points between them.

{233}_Dimensions._--Diameter of the outer shell 0.08 to 0.12, inner 0.06 to 0.08; pores of the former 0.015 to 0.02, of the latter 0.007 to 0.012; length of the spines 0.02.

_Habitat._--Central Pacific, Stations 268 to 274, surface.

Subgenus 2. _Haliommetta_, Haeckel.

_Definition._--Pores of the cortical shell regular, of nearly equal size and similar form; the spines not covering the entire surface, but scattered at intervals (their number smaller than that of the nodal-points of the network).

10. _Haliomma circumtextum_, n. sp. (Pl. 28, figs. 7, 7_a_).

Cortical shell very delicate, with thin thread-like bars, and regular, hexagonal pores, little larger than the thick-walled medullary shell (= 7 : 6). Pores of the latter regular, circular, double-edged, with hexagonal frames, of the same breadth as the bars; from all the hexagon-corners arise thin bristle-shaped, radial spines, twice as long as the diameter of the pores, becoming connected at equal distances from the centre by tangential threads, regularly disposed, forming the cortical shell. Twelve strong, three-sided pyramidal, radial spines, as broad at the base as one mesh, and about half as long as the radius of the shell.

_Dimensions._--Diameter of the outer shell 0.14, of the inner 0.12; pores of the former 0.012, of the latter 0.005; length of the radial spines 0.04, basal breadth 0.012.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

11. _Haliomma duodecinum_, n. sp.

Cortical shell thick walled, three times as broad as the medullary shell. Both shells with regular, circular pores, twice as broad as the bars; eight to ten on the radius of the outer, five to six on the radius of the inner shell. Twelve conical, regularly disposed radial spines, as long as the radius, and as broad at the base as one mesh.

_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.04; pores of the former 0.005, of the latter 0.002; length of the spines 0.05, basal breadth 0.005.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

12. _Haliomma megaporum_, Ehrenberg.

_Haliomma megaporum_, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 313.

Cortical shell thin walled, three times as broad as the medullary shell; the pores regular, circular, three to four on the radius, eight times as broad as the bars, quite as broad as the medullary shell, the pores of which are much smaller, twice as broad as the bars. Eight radial spines regularly disposed, conical, as long as the radius. (As the diagnosis of Ehrenberg is very {234}incomplete, and no figure is given with it, it remains doubtful whether his Mediterranean species be identical with my Atlantic variety.)

_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.04; pores of the former 0.04, of the latter 0.008; length of the spines 0.06.

_Habitat._--Mediterranean (Grecian shore); North Atlantic, Station 354, surface.

13. _Haliomma oculatum_, Ehrenberg.

_Haliomma oculatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 74, Taf. xxviii. figs. 2, 3.

Cortical shell thick walled, four times as broad as the medullary shell; its pores regular, circular, four times as broad as the bars, six to eight on the radius. Pores of the medullary shell regular, hexagonal, with very thin bars, three to four on the radius. Nine radial spines, regularly disposed, conical, as long as the radius, as broad at the base as one cortical pore. (In the specimen figured by Ehrenberg, only two spines were preserved, seven being accidentally broken off.)

_Dimensions._--Diameter of the outer shell 0.16, of the inner 0.04; pores of the former 0.01, of the latter 0.005.

_Habitat._--Fossil in Barbados.

14. _Haliomma enneaxiphos_, n. sp.

Cortical shell thick walled, four times as broad as the dark medullary shell, with regular, circular, hexagonally framed pores, twice as broad as the bars; eight to ten on the radius. Nine radial spines regularly disposed, three sided pyramidal, as long as the radius, as broad at the base as one mesh.

_Dimensions._--Diameter of the outer shell 0.11, of the inner 0.03; cortical pores 0.008, bars 0.004; length of the radial spines 0.05, basal breadth 0.012.

_Habitat._--Central Pacific, Station 272, surface.

15. _Haliomma tenuispinum_, J. Müller.

_Haliomma tenuispinum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 39, Taf. iv. fig. 9.

_Haliomma tenuispinum_, Haeckel, 1862, Monogr. d. Radiol., p. 431.

Cortical shell thin walled, three times as broad as the medullary shell. Both shells with very fine, thread-like bars, and regular, hexagonal pores; five to seven on the radius. Twenty radial spines, very thin, bristle-shaped, as long as the radius.

_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.04; pores of the former 0.016, of the latter 0.006.

_Habitat._--Mediterranean (Nice); North Atlantic, Station 353, surface.

{235}16. _Haliomma longispinum_, J. Müller.

_Haliomma longispinum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 39, Taf iv. fig. 8.

_Haliomma longispinum_, Haeckel, 1862, Monogr. d. Radiol., p. 431.

Cortical shell thick walled, three times as broad as the dark medullary shell. Pores regular, circular, hexagonally framed, twice as broad as the bars; four to six on the radius. Twenty radial spines, very long, regularly disposed, four to five times as long as the diameter of the shell, three-sided prismatic, with elegantly dentated edges, as broad as one cortical mesh.

_Dimensions._--Diameter of the outer shell 0.08, of the inner 0.03; pores of the former 0.01, bars 0.005; length of the spines 0.3 to 0.4.

_Habitat._--Mediterranean (Nice); Central Pacific, Station 272, surface.

17. _Haliomma capense_, n. sp.

Cortical shell thick walled, twice as broad as the medullary shell, both with regular, circular pores, twice as broad as the bars; eight to ten on the radius of the outer, four to six on the radius of the inner shell. Forty to sixty radial spines, conical, as long as the radius, as broad as one cortical pore.

_Dimensions._--Diameter of the outer shell 0.11, of the inner 0.05; pores of the former 0.01, bars 0.005; length of the spines 0.006, basal breadth 0.012.

_Habitat._--Cape of Good Hope, Station 142, surface.

18. _Haliomma denticulatum_, n. sp.

Cortical shell thick walled, three times as broad as the dark medullary shell, with regular, circular, double-edged pores, of the same breadth as the bars; eight to ten on the radius. Thirty to fifty radial spines, three-sided pyramidal, half as long as the radius, with three denticulated edges. (Very similar to _Actinomma denticulatum_, Pl. 29, fig. 3, but with simple medullary shell.)

_Dimensions._--Diameter of the outer shell 0.12, inner 0.04; pores and bars of the former 0.008; length of the spines 0.04, basal breadth 0.01.

_Habitat._--North Pacific, Station 244, depth 2900 fathoms.

19. _Haliomma grande_, n. sp.

Cortical shell thick walled, five times as broad as the dark medullary shell, with small, regular, circular pores, half as broad as the bars; twenty to twenty-four on the radius. One hundred to one hundred and twenty conical radial spines, five times as long as broad, only half as long as the radius.

_Dimensions._--Diameter of the outer shell 0.4, inner 0.08; pores of the outer 0.006, bars 0.012; length of the spines 0.1, basal breadth 0.02.

_Habitat._--Equatorial Atlantic, Station 348, depth 2450 fathoms.

{236}Subgenus 3. _Haliommilla_, Haeckel.

_Definition._--Pores of the cortical shell irregular, of different size and form; spines covering the entire surface (commonly one spine at each nodal-point).

20. _Haliomma capillaceum_, Haeckel.

_Haliomma capillaceum_, Haeckel, 1862, Monogr. d. Radiol., p. 426, Taf.
xxiii. fig. 2.

Cortical shell very thin walled, seven to eight times as broad as the medullary shell, both with irregular, polygonal pores, and very thin thread-like bars; outer pores twice to three times as broad as the inner. Radial spines very numerous, straight, bristle-shaped, about as long as the diameter of the medullary shell.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.025 to 0.03; outer pores 0.02 to 0.04, inner 0.008 to 0.016, bars 0.001; length of the spines 0.02 to 0.03.

_Habitat._--Mediterranean (Messina), Atlantic (Canary Islands), surface.

21. _Haliomma erinaceum_, Haeckel.

_Haliomma erinaceum_, Haeckel, 1862, Monogr. d. Radiol., p. 427, Taf.
xxiii. figs. 3, 4.

Cortical shell thin walled, seven to eight times as broad as the medullary shell, both with irregular, polygonal pores, two to ten times as broad as the bars, outer pores much larger than the inner. Radial spines very numerous, bristle-shaped, as long as the diameter of the medullary shell, the majority or all being either curved or obliquely depressed, the greater part neither straight nor radial.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.025 to 0.03; outer pores 0.005 to 0.03, inner 0.008 to 0.016, bars 0.002 to 0.004; length of the spines 0.03.

_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.

22. _Haliomma tenellum_, Haeckel.

_Haliomma tenellum_, Haeckel, 1862, Monogr. d. Radiol., p. 428.

_Haliomma spinuloso affine_, J. Müller, 1858, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 40, Taf. iv. fig. 7.

Cortical shell thin walled, three times as broad as the medullary shell, with irregular, roundish pores, and very thin bars. Pores of the inner shell regular, circular. Radial spines very numerous, bristle-shaped, straight, as long as the radius of the outer shell.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; outer pores 0.008 to 0.016, inner 0.005; length of the spines 0.07.

_Habitat._--Mediterranean (Nice); Atlantic, Stations 349 to 354, surface.

{237}23. _Haliomma spinulosum_, J. Müller.

_Haliomma spinulosum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 39, Taf. iv. fig. 6.

Cortical shell thin walled, twice as broad as the medullary shell, with irregular, polygonal pores, and very thin bars. Pores of the inner shell subregular, hexagonal, ten to twelve times as broad as the bars. Radial spines very numerous, bristle-shaped, one-sixth to one-fourth as long as the radius of the outer shell.

_Dimensions._--Diameter of the outer shell 0.16, inner 0.08; outer pores 0.01 to 0.03, inner 0.02; length of the spines 0.02 to 0.03.

_Habitat._--Mediterranean (Nice); Central Pacific, Station 266, surface.

24. _Haliomma rhodococcus_, n. sp. (Pl. 19, fig. 6).

_Sethosphæra rhodococcus_, Haeckel, 1879, Atlas, pl. xix. fig. 6.

Cortical shell very thin walled, little larger than the thick walled medullary shell (= 10 : 9). Pores of the outer shell very irregular, roundish, twice to six times as broad as the bars, about twenty on the radius. Pores of the inner shell twice as broad as the bars, six to eight on the radius, very regular, circular on the inner, six-lobed on the outer opening, separated by prominent hexagonal crests; in the hexagon-corners arise short conical radial spines, which at equal distances from the centre are united by the outer shell, but are prominent over its surface. (A very peculiar form; the two shells may better be regarded as inner and outer cortical shell.)

_Dimensions._--Diameter of the outer shell 0.2, inner 0.18; outer pores 0.04 to 0.012, inner 0.01; length of the spines 0.01.

_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms; also fossil in Barbados.

25. _Haliomma boreale_, n. sp.

Cortical shell thick walled, four times as broad as the medullary shell, with irregular, roundish pores, twice to four times as broad as the bars; eight to ten on the radius. Pores of the inner shell regular, circular, twice as broad as the bars, four to six on the radius. Radial spines very numerous, conical, nearly as long as the diameter of the shell.

_Dimensions._--Diameter of the outer shell 0.24, inner 0.06; outer pores 0.008 to 0.02, bars 0.005, inner pores 0.006, bars 0.003; length of the spines 0.2.

_Habitat._--Arctic Ocean, Greenland ("Alert" Expedition).

Subgenus 4. _Haliommura_, Haeckel.

_Definition._--Pores of the cortical shell irregular, of different size and form; spines not covering the entire surface, but scattered at intervals (their number smaller than that of the nodal-points in the network).

{238}26. _Haliomma macrodoras_, n. sp. (Pl. 28, figs. 6, 6_a_).

Cortical shell thin walled, twice as broad as the medullary shell, with irregular, polygonal meshes, three to six times as broad as the bars. Inner shell with regular, hexagonal meshes, ten times as broad as the bars. Twenty radial spines, very long, stout, three-sided prismatic, two to four times as long as the diameter of the shell, as broad as one medullary mesh, with three wing-like, denticulated edges. At the base of each spine three supporting curved beams.

_Dimensions._--Diameter of the outer shell 0.14 to 0.16, of the inner 0.07 to 0.08; outer pores 0.01 to 0.02, bars 0.003; inner pores 0.01, bars 0.001; length of the spines 0.3 to 0.6, breadth 0.01.

_Habitat._--Central Pacific, Station 271, surface.

27. _Haliomma antarcticum_, n. sp.

Cortical shell very thin walled, three times as broad as the medullary shell, with irregular, polygonal pores, and very thin thread-like bars. Inner shell with regular, hexagonal meshes, six times as broad as the bars. About forty radial spines, angular, pyramidal, half as long as the radius of the shell, as broad at the base as the largest mesh.

_Dimensions._--Diameter of the outer shell 0.2, of the inner 0.07; outer pores 0.006 to 0.015, inner 0.008; length of the spines 0.05, basal breadth 0.012.

_Habitat._--Antarctic Ocean, Station 154, surface.

28. _Haliomma wyvillei_, Haeckel.

_Haliomma wyvillei_, Haeckel, 1878, Protistenreich, p. 44, fig. 31.

_Haliomma species_, Wyville Thomson, 1877, Atlantic, vol. i. p. 236, fig.
54.

Cortical shell thin walled, three times as broad as the medullary shell. Both shells with irregular, large, polygonal pores, and very thin bars. From the inner shell arise very numerous (eighty to one hundred and twenty or more) radial spines, which pierce the outer shell, and are outside it, as long as the radius of the inner shell, straight, bristle-shaped, and as thick as the bars.

_Dimensions._--Diameter of the outer shell 0.18, of the inner 0.06; pores 0.01 to 0.02, bars 0.001 to 0.002; length of the free spines 0.06.

_Habitat._--Central Pacific, Stations 266 to 274, surface.

29. _Haliomma beroes_, Ehrenberg.

_Haliomma beroes_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvB. B. iv. fig.
19.

_Haliomma beroes_, Haeckel, 1862, Monogr. d. Radiol., p. 434.

Cortical shell thin walled, three times as broad as the medullary shell, with irregular, roundish pores, twice to four times as broad as the bars. Inner shell with regular, circular pores, twice as broad as the bars. Both shells connected by four (or six ?) radial beams, perpendicularly crossed. Thirty to forty radial spines, conical, thin, shorter than the radius.

_Dimensions._--Diameter of the outer shell 0.11, inner 0.04; outer pores 0.007 to 0.012, inner 0.005; length of the spines 0.03, basal breadth 0.005.

_Habitat._--Atlantic, depth 2000 fathoms.

{239}30. _Haliomma compactum_, n. sp. (Pl. 28, figs. 5, 5_a_).

Cortical shell very thick walled, four times as broad as the thin walled medullary shell; pores of the former irregular, roundish, with high polygonal frames of very different size, twice to four times as broad as the bars. Inner shell with simple, small, polygonal pores, connected with the outer shell by eight (?) regularly disposed thin radial beams, opposite in pairs, prolonged outside into strong conical spines, longer than the radius.

_Dimensions._--Diameter of the outer shell 0.08, inner 0.02; outer pores 0.005 to 0.01, inner 0.005; length of the spines 0.06, basal breadth 0.012.

_Habitat._--Central Pacific, Stations 265 to 272, depth 2425 to 2925 fathoms.

31. _Haliomma permagnum_, n. sp.

Cortical shell thick walled, six times as broad as the medullary shell, with irregular, roundish, double-edged pores, three to six times as broad as the bars. Inner shell with regular, circular pores, twice as broad as the bars. One hundred and twenty to one hundred and fifty radial spines, conical, only one-fourth as long as the radius.

_Dimensions._--Diameter of the outer shell 0.42, inner 0.07; outer pores 0.012 to 0.025, bars 0.004; inner pores 0.008, bars 0.004; length of the spines 0.05, basal breadth 0.03.

_Habitat._--Central Pacific, Station 268, surface.

32. _Haliomma patagonicum_, n. sp.

Cortical shell thick walled, four times as broad as the medullary shell, with irregular, roundish pores, twice to three times as broad as the bars. Inner shell also with irregular, roundish pores, of half the size. Forty to fifty radial spines, cylindro-conical, about as long as the shell diameter.

_Dimensions._--Diameter of the outer shell 0.24, inner 0.06; outer pores 0.012 to 0.02, bars 0.006; inner pores 0.005 to 0.01, bars 0.004; length of the spines 0.3, breadth 0.02.

_Habitat._--South-east Pacific, west coast of Patagonia, Station 302, surface.

33. _Haliomma clavatum_, n. sp.

Cortical shell thick walled, three times as broad as the medullary shell, with irregular, roundish pores little larger than the bars; eight to twelve on the radius. Inner shell with similar but smaller pores. About twenty radial spines, club-shaped, as long as the radius, three-sided, with prominent edges, twice as broad at the distal end as at the base. (Similar to _Acanthosphæra clavata_, Pl. 26, fig. 8, but differs from it in the possession of a medullary shell.)

_Dimensions._--Diameter of the outer shell 0.2, inner 0.06; outer pores and bars 0.008 to 0.02, inner 0.006 to 0.01; length of the spines 0.1, distal breadth 0.03.

_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.

{240}Genus 95. _Heliosoma_,[130] Haeckel, 1881, Prodromus, p. 452.

_Definition._--#Astrosphærida# with one medullary (intracapsular) and one cortical (extracapsular) shell, the two being connected by radial beams piercing the central capsule. Shell surface covered with simple radial spines of two different kinds; larger main spines and smaller by-spines.

The genus _Heliosoma_ differs from the preceding _Haliomma_ in the possession of two different kinds of radial spines, and exhibits therefore the same relation to it that _Heliosphæra_ bears to _Acanthosphæra_ among the Coscinommida. The smaller by-spines are much more numerous than the larger main spines.

Subgenus 1. _Heliosomantha_, Haeckel.

_Definition._--Pores of the cortical shell regular, of nearly equal size and similar form.

1. _Heliosoma radians_, n. sp. (Pl. 28, figs. 3, 3_a_).

Cortical shell very thin walled, with thread-like bars and regular, hexagonal meshes; twenty to twenty-two on the radius. Medullary shell only one-fifth as large, of the same structure. The two shells connected by twenty very thin radial beams, which are prolonged outside into twenty stout, three-sided pyramidal main spines, as long as the diameter of the inner shell. Between these, arising from the surface, numerous bristle-shaped by-spines.

_Dimensions._--Diameter of the outer shell 0.25, inner 0.05, pores 0.012; length of the main spines 0.05, basal breadth 0.012.

_Habitat._--Central Pacific, Stations 266 to 274, surface.

2. _Heliosoma elegans_, n. sp.

Cortical shell thick walled, with regular, circular, hexagonally framed pores, twice as broad as the bars; ten to twelve on the radius. Medullary shell half as large, with simple, regular, circular pores, twice as broad as the bars. The two shells connected by twenty very thin radial beams, which are prolonged outside into twenty slender, three-sided pyramidal main spines as long as the radius. In each corner of the surface hexagons a bristle-shaped by-spine one-fourth as long.

_Dimensions._--Diameter of the outer shell 0.12, inner 0.06; outer pores 0.006, bars 0.003; length of the main spines 0.05, basal breadth 0.01.

_Habitat._--Central Pacific, Station 271, surface.

3. _Heliosoma echinaster_, Haeckel.

_Haliomma echinaster_, Haeckel, 1862, Monogr. d. Radiol., p. 429, Taf.
xxiv. figs. 1-3.

Cortical shell thin walled, with regular, circular, hexagonally framed pores, twice as broad as the bars; ten to twelve on the radius. Medullary shell one-fourth as large, with few irregular, large, {241}polygonal pores and very thin thread-like bars, connected with the former by nine similar thin radial beams, which are prolonged outside into nine pyramidal main spines, as long as the radius. From each corner of the surface hexagon arises a bristle-shaped by-spine, half as long as the main spine.

_Dimensions._--Diameter of the outer shell 0.16, inner 0.04; outer pores 0.008, bars 0.004; length of the main spines 0.08, basal breadth 0.01.

_Habitat._--Mediterranean (Messina), surface.

4. _Heliosoma duodecilla_, n. sp.

Cortical shell thick walled, with regular, circular pores, of the same breadth as the bars; sixteen to eighteen on the radius. Medullary shell one-third as large, of the same structure. Twelve radial main spines, regularly disposed, cylindro-conical, longer than the shell diameter, as broad as two pores. Whole surface covered with short conical by-spines.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; outer pores and bars 0.007; length of the main spines 0.2, breadth 0.02.

_Habitat._--South Atlantic, Station 333, surface.

Subgenus 2. _Heliosomura_, Haeckel.

_Definition._--Pores of the cortical shell irregular, of different size and form.

5. _Heliosoma hastatum_, n. sp. (Pl. 28, fig. 4).

Cortical shell very thin walled, with large, irregular, polygonal meshes, three to six times as broad as the bars; four to six on the radius. Medullary shell one-third as large, with small, regular, circular pores. The two shells connected by twelve regularly disposed radial beams, which are prolonged outside into twelve very stout three-sided pyramidal main spines, somewhat longer than the radius, spear-shaped; each of the three wings in the middle part with one tooth. Scattered on the surface numerous by-spines of the same form, half as long and only one-fourth as broad.

_Dimensions._--Diameter of the outer shell 0.1, inner 0.033; outer pores 0.006 to 0.013, inner pores 0.002, bars 0.002; length of the main spines 0.06, breadth 0.015.

_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.

6. _Heliosoma indicum_, n. sp.

Cortical shell thick walled, with irregular, roundish pores, twice to five times as broad as the bars. Medullary shell of the same structure, only one-fourth as large. Thirty to forty conical main spines, as long as the radius; between them numerous bristle-shaped by-spines, only half as long.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.05; outer pores 0.004 to 0.01, bars 0.002; length of the main spines 0.1, breadth 0.01.

_Habitat._--Indian Ocean, between Aden and Socotora, surface, Haeckel.

{242}Genus 96. _Elatomma_,[131] n. gen.

_Definition._--#Astrosphærida# with one medullary (intracapsular) and one cortical (extracapsular) shell, the two being connected by radial beams piercing the central capsule. Shell surface covered with branched radial spines.

The genus _Elatomma_ differs from _Haliomma_ in the ramification of the radial spines, and exhibits therefore the same relation to it that _Cladococcus_, among the Coscinommida, bears to _Acanthosphæra_.

Subgenus 1. _Elatommella_, Haeckel.

_Definition._--Pores of the cortical shell regular, of nearly equal size and similar form.

1. _Elatomma pinetum_, n. sp.

Cortical shell thick walled, with regular, circular, hexagonally framed pores, three times as broad as the bars. From its surface arise twenty to thirty large, three-sided prismatic, radial spines as long as the shell diameter, branched like a pine tree; on each edge of the spine five to six ramified branches, decreasing in size towards the distal end. Similar to _Cladococcus pinetum_ (Pl. 27, figs. 1, 3), but differing in the possession of a medullary shell (one-third as large as the outer), with regular, circular pores, as broad as the bars.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.07; cortical pores 0.012, bars 0.004; length of the spines 0.2 to 0.24.

_Habitat._--Central Pacific, Stations 266 to 272, surface.

2. _Elatomma scoparium_, n. sp.

Cortical shell thick walled, with regular, circular pores, twice as broad as the bars, connected with the medullary shell by twenty thin radial beams, which are prolonged outside into twenty large cylindrical radial spines somewhat longer than the radius; in the proximal half simple, in the distal half with six to nine dichotomous, irregular branches. Similar to _Cladococcus scoparius_ (Pl. 27, fig. 2), but much larger, and with a large medullary shell (one-third as broad as the outer), and regular, circular pores.

_Dimensions._--Diameter of the outer shell 0.12, inner 0.04; cortical pores 0.01, bars 0.005; length of the spines 0.08.

_Habitat._--North Pacific, Station 240, surface.

Subgenus 2. _Elatommura_, Haeckel.

_Definition._--Pores of the cortical shell irregular, of different size or form.

{243}3. _Elatomma juniperinum_, n. sp. (Pl. 28, fig. 8).

Cortical shell thin walled, with regular, polygonal, or roundish pores, twice to four times as broad as the bars, connected with the small medullary shell by about twenty thin radial beams. Inner shell only one-eighth as broad as the outer, with few irregular, polygonal meshes. Surface covered with very numerous (one hundred to one hundred and fifty or more) branched conical radial spines, one-third as long as the shell radius, with six to twelve short lateral branches.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.025; cortical pores 0.08 to 0.016, bars 0.004; length of the spines 0.04.

_Habitat._--Central Pacific, Station 271, surface.

4. _Elatomma penicillus_, n. sp.

Cortical shell thin walled, with irregular, polygonal pores, twice to four times as broad as the bars, connected with the medullary shell by twenty (or more?) very thin beams. These are prolonged outside into twenty straight, three-sided prismatic, radial spines as long as the radius, with a brush-like bunch of six to nine short, irregularly ramified branches at the end. Medullary shell very delicate (half as broad as the outer), with regular, hexagonal meshes and thread-like bars.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.08; length of the spines 0.08.

_Habitat._--West coast of Norway, Bergen, Haeckel.

5. _Elatomma irregulare_, n. sp.

Cortical shell thin walled, with irregular, polygonal, or roundish meshes, twice to six times as broad as the bars; the medullary shell of the same structure, half as broad, with smaller irregular pores. Forty to sixty curved, three-sided, radial spines, as long as the shell, with a bunch of very irregular, curved, and partly ramified branches at the distal end.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.1; length of the spines 0.2, breadth 0.01.

_Habitat._--North Atlantic, Gulf Stream, Færöe Channel, surface, John Murray.

Genus 97. _Leptosphæra_,[132] n. gen.

_Definition._--#Astrosphærida# with two extracapsular cortical shells without by-spines, connected by long prismatic radial spines.