Subfamily Coscinommida, Haeckel.

Heliosphærida, Haeckel, 1881, Prodromus, pp. 449, 450.

Definition.—Astrosphærida with one single spherical lattice-shell.

Genus 88. Acanthosphæra,^[122] Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d.

Definition.—Astrosphærida with one simple lattice-sphere, covered with simple radial spines of the same kind.

The genus Acanthosphæra exhibits the most simple form of all Astrosphærida; a simple spherical lattice-shell, the surface of which is covered by radial spines of one and the same kind. The number of the latter is very variable, often twelve to twenty, regularly disposed; in other cases forty to sixty or more; and sometimes at each nodal-point of the network a spine is developed.

Subgenus 1. Rhaphidococcus, Haeckel, 1862, Monogr. d. Radiol., p. 365 (sensu emendato).

Definition.—Pores of the spherical shell regular or subregular, all of nearly equal size and similar form. Radial spines arising from all the nodal-points of the network.

1. Acanthosphæra tenuissima, Haeckel.

Shell extremely thin walled, eight to ten times as broad as one pore. Meshes or pores regular, hexagonal, with thread-like bars; five to seven on the radius. At each nodal-point (between every three meshes) arises a bristle-shaped radial spine, as long as the diameter of one pore.

Dimensions.—Diameter of the shell 0.2 to 0.25, of the meshes or pores 0.025 to 0.03, bars below 0.0001; length of the spines 0.03.

Habitat.—Mediterranean (Messina), North Atlantic (Canary Islands).

2. Acanthosphæra tenuis, n. sp.

Shell very thin walled, about twenty times as broad as one pore. Meshes subregular, hexagonal, with thread-like bars; twelve to fourteen on the radius. At each nodal-point arises a bristle-shaped radial spine, about as long as the radius.

Dimensions.—Diameter of the shell 0.3 to 0.35, pores 0.015 to 0.018, bars below 0.001; length of the spines 0.12 to 0.16.

Habitat.—Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms.

3. Acanthosphæra macropora, n. sp.

Shell thin walled, five to six times as broad as one mesh. Pores regular, circular, hexagonally framed, ten to twelve times as broad as the bars. Radial spines bristle-shaped, as long as the diameter of one pore, arising from all the nodal-points.

Dimensions.—Diameter of the shell 0.07 to 0.08, pores 0.012, bars 0.001; length of the spines 0.012.

Habitat.—Central Pacific, Station 271, surface.

4. Acanthosphæra micropora, n. sp.

Shell thick walled, forty to fifty times as broad as one pore. Pores regular, circular, hexagonally framed, half as broad as the bars. Radial spines bristle-shaped, as long as the radius of the shell, arising from all the nodal-points.

Dimensions.—Diameter of the shell 0.22, pores 0.003, bars 0.006; length of the spines 0.1.

Habitat.—South Pacific, Station 288, surface.

5. Acanthosphæra dentata, Haeckel.

Shell thin walled, eight to ten times as broad as one pore. Pores regular, circular, hexagonally framed, three times as broad as the bars. Radial spines arising from all the nodal-points of the network, three-sided prismatic, with dentated or serrated edges, longer than the shell diameter.

Dimensions.—Diameter of the shell 0.08, pores 0.01, bars 0.003; length of the spines 0.1, breadth 0.003.

Habitat.—Mediterranean (Messina), surface.

6. Acanthosphæra acufera, Haeckel.

Shell thin walled, eight to ten times as broad as one mesh. Pores regular, circular, three times as broad as the bars. Radial spines bristle-shaped, arising with thicker conical bases from all the nodal-points, about as long as the diameter of the shell.

Dimensions.—Diameter of the shell 0.08, pores 0.01, bars 0.003; length of the spines 0.08.

Habitat.—Mediterranean (Messina); North Atlantic, Station 354, surface.

7. Acanthosphæra castanea, n. sp. (Pl. 26, fig. 3).

Shell thick walled, thirty times as broad as one mesh. Pores regular, circular, nearly of the same breadth as the bars. Radial spines bristle-shaped, arising with thicker conical bases from all the nodal-points, scarcely half as long as the radius of the shell.

Dimensions.—Diameter of the shell 0.15, pores and bars 0.005; length of the spines 0.03.

Habitat.—North Pacific, Station 244, surface.

8. Acanthosphæra flosculenta, n. sp.

Shell thick walled, thirteen times as broad as one mesh. Pores regular, circular, three times as broad as the bars, with an elegant six-lobed frame (Pl. 28, fig. 1b). In the intervals between the six lobes of each mesh arise six conical radial spines (half as long as the radius), six around each pore. (Differs from the similar Haliomma flosculentum, Pl. 28, fig. 1, in the absence of an enclosed medullary shell and the stronger development of the spines.)

Dimensions.—Diameter of the shell 0.13, pores 0.01, bars 0.003; length of the spines 0.03.

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

Subgenus 2. Rhaphidocapsa, Haeckel.

Definition.—Pores of the spherical shell regular or subregular, all of nearly equal size and similar form. Radial spines scattered at some distance apart, not at all the nodal-points.

9. Acanthosphæra insignis, Haeckel.

Shell thin walled, about ten times as broad as one mesh. Pores regular, hexagonal, ten to twelve times as broad as the bars. Radial spines about one hundred and twenty, arising from certain nodal-points of the network, being as long as the diameter of the sphere, three-sided prismatic, with three thin denticulated edges.

Dimensions.—Diameter of the shell 0.2, pores 0.02, bars 0.002; length of the spines 0.18, breadth 0.003.

Habitat.—Cosmopolitan; Mediterranean (Messina), Atlantic (Stations 325, 347), Indian (Ceylon), Pacific (Stations 270 to 274), surface.

10. Acanthosphæra fortispina, n. sp.

Shell thin walled, about six times as broad as one mesh. Pores subregular, hexagonal, with thread-like bars; three to four on the radius. Radial spines about twenty, three-sided pyramidal, as long as the diameter, and one-third as broad at the base as one pore.

Dimensions.—Diameter of the shell 0.06 to 0.09, pores 0.01 to 0.014, bars below 0.001; length of the spines 0.07 to 0.08, basal breadth 0.03 to 0.04.

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

11. Acanthosphæra mucronata, n. sp. (Pl. 26, fig. 7).

Shell thick walled, fifteen times as broad as one pore. Pores regular, circular, hexagonally framed, funnel-shaped, three times as broad as the bars. Radial spines twenty to thirty, dagger-shaped or spindle-shaped, angular, twice as broad in the middle as one pore, about as long as the radius.

Dimensions.—Diameter of the shell 0.11, pores 0.0075, bars 0.0025; length of the spines 0.06, breadth 0.015.

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

12. Acanthosphæra clavata, n. sp. (Pl. 26, fig. 8).

Shell thick walled, ten to twelve times as broad as one mesh. Pores subregular, circular, three times as broad as the bars. Radial spines twenty, club-shaped, angular, with prominent edges, twice as broad at the distal end as one pore, about as long as the radius.

Dimensions.—Diameter of the shell 0.11, pores 0.01, bars 0.003; length of the spines 0.06, breadth 0.02.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

13. Acanthosphæra marginata, n. sp.

Shell thick walled, twelve times as broad as one mesh. Pores regular, circular double-edged, four times as broad as the bars. Radial spines conical, fourteen in number, about as long as the radius, and as broad at the base as one mesh. Six spines correspond to the six corners of a regular octahedron, eight to the centre of the eight faces.

Dimensions.—Diameter of the shell 0.1, pores 0.008, bars 0.002; radial spines 0.06, basal breadth 0.01.

Habitat.—Central Pacific, Station 274, surface.

14. Acanthosphæra florida, n. sp.

Shell thick walled, fifteen times as broad as one mesh. Pores regular, circular, hexagonally lobed, separated by prominent funnel-shaped crests of half the breadth. Twenty conical radial spines, half as long as the radius, as broad at the base as one funnel.

Dimensions.—Diameter of the shell 0.15, pores 0.01, bars 0.005; length of the spines 0.04, basal breadth 0.02.

Habitat.—South Atlantic, Station 325, depth 2650 fathoms.

15. Acanthosphæra enneacantha, n. sp.

Shell thin walled, fourteen times as broad as one mesh. Pores regular, circular, twice as broad as the bars. Nine radial spines, regularly disposed, as long as the shell diameter, three-sided prismatic, with pyramidal apex, as broad as one mesh.

Dimensions.—Diameter of the shell 0.14, pores 0.01, bars 0.005; length of the spines 0.15, breadth 0.01.

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

16. Acanthosphæra octahedralis, n. sp.

Shell thick walled, octahedral, fourteen times as broad as one mesh. Pores regular, circular, three times as broad as the bars. Fourteen radial spines, regularly disposed, conical, as long as the radius of the shell, twice as broad at the base as one mesh. Six spines correspond to the six corners of a regular octahedron, eight to the central points of its eight faces.

Dimensions.—Diameter of the shell 0.14, pores 0.01, bars 0.003; length of the spines 0.08, basal breadth 0.02.

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

17. Acanthosphæra compacta, n. sp.

Shell thick walled, about sixty times as broad as one mesh. Pores regular, circular, twice as broad as the bars. Thirty to forty radial spines, three-sided pyramidal, scarcely half as long as the radius, five to six times as broad at the base as one pore.

Dimensions.—Diameter of the shell 0.24, pores 0.004, bars 0.002; length of the radial spines 0.05, basal breadth 0.02.

Habitat.—Fossil in Barbados.

Subgenus 3. Raphidodrymus, Haeckel.

Definition.—Pores of the spherical shell irregular, of different size or form. Radial spines arising from all the nodal-points of the network.

18. Acanthosphæra capillaris, n. sp.

Shell thin walled, with irregular polygonal meshes, twelve to twenty times as broad as the bars; eight to ten on the radius. Radial spines bristle-shaped, arising from all the nodal-points of the network, about as long as the diameter of the largest meshes.

Dimensions.—Diameter of the shell 0.15 to 0.2, pores 0.012 to 0.02, bars 0.001; length of the spines 0.02.

Habitat.—Central Pacific, Stations 260 to 274, surface.

19. Acanthosphæra arctica, n. sp.

Shell thin walled, with irregular roundish, polygonally framed meshes, three to four times as broad as the bars. Radial spines arising from all the nodal-points of the network, pyramidal at the base; in the distal half bristle-shaped, as long as the radius.

Dimensions.—Diameter of the shell 0.12, pores 0.006 to 0.008, bars 0.002; length of the spines 0.07.

Habitat.—Arctic Ocean, Greenland (in the stomach of Periphylla hyacinthina).

20. Acanthosphæra antarctica, n. sp.

Shell thick walled, with irregular, roundish pores, about as broad as the bars. Radial spines arising from all nodal-points of the network, conical at the base, half as long as the radius.

Dimensions.—Diameter of the shell 0.15, pores and bars 0.005 to 0.008; length of the spines 0.04.

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

Subgenus 4. Rhaphidosphæra, Haeckel, 1881, Prodromus, p. 450.

Definition.—Pores of the spherical shell irregular, of different size or form. Radial spines scattered at intervals, not at all the nodal-points.

21. Acanthosphæra echinoides, Haeckel.

Shell thin walled, with irregular polygonal or more roundish pores of very different size. Forty to fifty very large meshes, separated by rows of much smaller meshes. Radial spines forty to sixty, half as long as the shell radius, bristle-shaped, with conical bases.

Dimensions.—Diameter of the shell 0.13, larger pores 0.03, smaller 0.003; length of the spines 0.03.

Habitat.—Mediterranean (Nice), surface.

22. Acanthosphæra longispina, n. sp.

Shell thin walled, with irregular polygonal meshes, four to six times as broad as the bars; six to eight on the radius. Thirty to forty radial spines, three-sided prismatic, twice as broad as the bars, twice to three times as long as the diameter of the shell.

Dimensions.—Diameter of the shell 0.12 to 0.15, pores 0.012 to 0.02, bars 0.003; length of the radial spines 0.2 to 0.4, breadth 0.006.

Habitat.—North Pacific, Station 253, surface.

23. Acanthosphæra brevispina, n. sp.

Shell thick walled, with irregular polygonal meshes, twice to four times as broad as the bars; twelve to sixteen on the radius. Sixty to eighty radial spines, pyramidal, half as long as the radius of the shell, one-fourth as broad at the base.

Dimensions.—Diameter of the shell 0.2 to 0.22, pores 0.006 to 0.012, bars 0.003; length of the spines 0.05, basal breadth 0.02.

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

24. Acanthosphæra acanthica, Haeckel.

Shell thick walled, with irregular, roundish pores, twice to three times as broad as the bars; seven to nine on the radius. Ten to twenty radial spines pyramidal, shorter than the radius, twice as broad at the base as one mesh.

Dimensions.—Diameter of the shell 0.12 to 0.16, pores 0.006 to 0.009, bars 0.003; length of the spines 0.04 to 0.06, basal breadth 0.01 to 0.015.

Habitat.—Fossil in Tertiary rocks of Sicily and Barbados.

25. Acanthosphæra haliphormis, Ehrenberg.

Shell thick walled, with irregular, roundish pores, twice to four times as broad as the bars; four to five on the radius. Twelve to twenty radial spines pyramidal, longer than the radius, scarcely as broad as one mesh at the base.

Dimensions.—Diameter of the shell 0.11, pores 0.01 to 0.02, bars 0.005; length of the spines 0.06 to 0.08, basal breadth 0.01.

Habitat.—Arctic Ocean, near Greenland, depth 1000 fathoms.

26. Acanthosphæra angulata, n. sp. (Pl. 26, fig. 4).

Shell thin walled; its pores irregular, roundish, with angular, double-edged margin, two to four times as broad as the bars; six to eight on the radius. Twenty to thirty radial spines pyramidal, angular, with prominent edges, shorter than the radius, as broad at the base as one small mesh.

Dimensions.—Diameter of the shell 0.2, pores 0.02 to 0.04, bars 0.01; length of the spines 0.06, basal breadth 0.02.

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

27. Acanthosphæra conifera, n. sp.

Shell thick walled, with irregular, roundish pores, twice to five times as broad as the bars; ten to twelve on the radius. Twenty radial spines conical, regularly disposed, half as long as the radius, as broad at the base as one of the largest meshes.

Dimensions.—Diameter of the shell 0.2, pores 0.008 to 0.02, bars 0.004; length of the spines 0.05, basal breadth 0.02.

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

28. Acanthosphæra maxima, n. sp.

Shell thick walled, with irregular, roundish pores, twice to eight times as broad as the bars; twelve to twenty on the radius. Radial spines very numerous (two to three hundred), short, conical, scarcely as long as the diameter of the largest meshes, and one-third as broad.

Dimensions.—Diameter of the shell 0.3 to 0.4, pores 0.008 to 0.03, bars 0.004; length of the radial spines 0.03, basal breadth 0.01.

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

29. Acanthosphæra simplex, Haeckel.

Shell thick walled, with irregular, roundish pores, three to six times as broad as the bars; eight to nine on the radius. Forty to sixty radial spines, about as long as the diameter of the shell, three-sided prismatic, not straight, but more or less bent.

Dimensions.—Diameter of the shell 0.12, pores 0.005 to 0.012, bars 0.0015 to 0.02; length of the spines 0.12, breadth 0.003.

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

30. Acanthosphæra gibbosa, n. sp.

Shell thin walled, rugged or tuberculate, covered by about twenty hill-shaped tubercles or protuberances with flat valleys between them. Network very delicate, with thread-like bars and irregular, polygonal pores; twenty to thirty on the radius. Radial spines very numerous, bristle-shaped, twice to three times as long as the diameter of the pores.

Dimensions.—Diameter of the shell 0.3, pores 0.01 to 0.02; length of the spines 0.02 to 0.05.

Habitat.—Central Pacific, Station 274, surface.

31. Acanthosphæra reticulata, n. sp. (Pl. 26, fig. 5).

Shell thick walled, with irregular, roundish pores, twice to four times as broad as the bars; six to eight on the radius. Surface of the bars covered with a peculiar delicate network of very fine crests. Twenty to forty radial spines, angular, pyramidal, scarcely one-third as long as the radius of the shell, as broad at the base as the bars.

Dimensions.—Diameter of the shell 0.22, pores 0.02 to 0.04, bars 0.01; length of the spines 0.04, basal breadth 0.01.

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

Genus 89. Heliosphæra,^[123] Haeckel, 1862, Monogr. d. Radiol., p. 350 (sensu emendato).

Definition.—Astrosphærida with one simple lattice-sphere, covered with simple radial spines of two different kinds: larger main spines and smaller by-spines.

The genus Heliosphæra (in the mended definition here employed) differs from the foregoing Acanthosphæra in the possession of two different kinds of radial spines: larger main spines scattered on the surface or disposed regularly in limited numbers (twelve to twenty, sometimes forty to fifty or more), and smaller by-spines in much larger numbers, arising from all the nodal-points of the network (or sometimes also from its bars).

Subgenus 1. Heliosphærella, Haeckel.

Definition.—Pores of the shell regular or subregular, all of nearly equal size and similar form.

1. Heliosphæra hexagonaria, n. sp. (Pl. 26, fig. 2).

Shell very thin walled, about twenty times as broad as one pore. Meshes or pores subregular, hexagonal, with thread-like bars; fifteen to seventeen on the radius. Radial spines at the nodal-points of the network; about forty main spines three-sided pyramidal, half as broad at the base as one pore, and twice as long as the bristle-shaped by-spines, which are very numerous, and as long as the diameter of one pore.

Dimensions.—Diameter of the shell 0.25 to 0.3, of the meshes or pores 0.012 to 0.015, bars below 0.001; length of the main spines 0.03, basal breadth 0.007.

Habitat.—Central Pacific, Stations 272 to 274, depth 2350 to 2750 fathoms.

2. Heliosphæra actinota, Haeckel.

Shell very thin walled, about ten times as broad as one mesh. Pores regular, hexagonal, with thread-like bars; six to eight on the radius. Radial spines at the nodal-points of the network, bristle-shaped, scarcely broader than the bars; about twenty main spines as long as the diameter of the shell, and numerous by-spines, only one-third to one-half as long as the former.

Dimensions.—Diameter of the shell 0.2 to 0.25, of the meshes 0.02 to 0.03, bars below 0.001; length of the main spines 0.2 to 0.3.

Habitat.—Mediterranean (Messina), Atlantic (Canaries, Azores), surface.

3. Heliosphæra echinoides, Haeckel.

Shell thin walled, about six times as broad as one mesh. Pores regular, hexagonal, eight times as broad as the bars. Radial spines arising, not from the nodal-points of the network, but from the midst of the bars (very rare disposition!); twenty main spines regularly disposed, as long as the radius, four times as long as the numerous by-spines; all spines bristle-shaped, of the same breadth as the bars.

Dimensions.—Diameter of the shell 0.09, pores 0.015, bars 0.002; length of the main spines 0.04.

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

4. Heliosphæra elegans, Haeckel.

Shell very thin walled, about ten times as broad as one mesh. Pores regular, hexagonal, with thread-like bars, which are crossed by tangential bars, so that each side of a hexagon exhibits a regular rectangular cross (exactly the same as in Pl. 19, fig. 5). All radial spines bristle-shaped, as thin as the bars, and arising from the nodal-points; twenty main spines as long as the radius, numerous by-spines scarcely one-sixth as long.

Dimensions.—Diameter of the shell 0.26, pores 0.026, bars below 0.001; length of the main spines 0.13.

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

5. Heliosphæra pectinata, n. sp. (Pl. 26, fig. 9).

Shell thick walled, combed, about fourteen times as broad as one mesh. Pores subregular, circular, with elevated hexagonal frames, three times as broad as the bars. Radial spines very numerous and stout; thirty to forty main spines, three-sided pyramidal, nearly as long as the radius, as broad as one mesh; by-spines small, conical, everywhere scattered at the nodal-points of the network and on the high combs of the bars.

Dimensions.—Diameter of the shell 0.16, pores 0.012, bars 0.004; length of the main spines 0.07, basal breadth 0.016.

Habitat.—West Tropical Pacific, Station 225, depth 4475 fathoms.

6. Heliosphæra coronata, n. sp. (Pl. 26, figs. 6, 6a).

Shell thick walled, about ten times as broad as one mesh. Pores regular, circular, five times as broad as the bars; each pore surrounded by a regular coronal of six short, conical by-spines (fig. 6a); twenty to thirty main spines, also conical, half as long as the radius, as broad as one pore.

Dimensions.—Diameter of the shell 0.15, pores 0.015, bars 0.003; length of the main spines 0.04, basal breadth 0.015.

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

7. Heliosphæra floribunda, n. sp.

Shell thick walled about ten times as broad as one mesh. Pores regular, six-lobed, twice as broad as the bars; each pore surrounded by six small conical by-spines (as in Pl. 28, figs. 1, 1b); twenty main spines regularly disposed cylindro-conical, as long as the diameter of the shell or longer.

Dimensions.—Diameter of the shell 0.15, pores 0.015, bars 0.008; length of the main spines 0.16, breadth 0.008.

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

8. Heliosphæra cristata, n. sp.

Shell thick walled, about twelve times as broad as one mesh. Pores subregular, circular, twice as broad as the bars; each pore surrounded by an elegant coronal of ten to twenty small, conical by-spines; twenty main spines regularly disposed, conical, only one-third as long as the radius, as broad at the base as one mesh.

Dimensions.—Diameter of the shell 0.25, pores 0.02, bars 0.01; length of the main spines 0.04, basal breadth 0.02.

Habitat.—South Pacific, Station 285, depth 2375 fathoms.

9. Heliosphæra castanella, n. sp.

Shell thick walled, about twenty times as broad as one mesh. Pores regular, circular, of the same breadth as the bars. Whole surface densely covered with innumerable bristle-shaped by-spines, half as long as the radius; fifty to eighty main spines, conical, nearly as long as the diameter, twice as broad at the base as one pore. (Very similar to some species of Castanella, Pl. 113, but without the osculum characteristic of this Phæodarian; may be easily confounded with it.)

Dimensions.—Diameter of the shell 0.3, pores 0.015, bars 0.015; length of the main spines 0.25, basal breadth 0.03.

Habitat.—North Pacific (Japan), Station 234, surface.

Subgenus 2. Heliosphæromma, Haeckel.

Definition.—Pores of the shell irregular, of different size or form.

10. Heliosphæra polygonaria, n. sp.

Shell very thin walled, with thread-like bars and irregular, polygonal pores (having four to eight angles, commonly five to seven); eight to ten on the radius. Radial spines at all the nodal-points of the network, bristle-shaped; forty to sixty main spines, as long as the radius, twice as thick as the numerous by-spines, which are not larger than one mesh.

Dimensions.—Diameter of the shell 0.15 to 0.2, pores 0.012 to 0.02, bars 0.001; length of the main spines 0.08 to 0.1.

Habitat.—Central Pacific, Stations 266 to 272, surface.

11. Heliosphæra heteracantha, n. sp.

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.