_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.

{214}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.

_Cyrtidosphæra echinoides_, Haeckel, 1865, Zeitschr. f. wiss. Zool., xv.

p. 367, Taf. xxvi. fig. 5.

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.

{215}_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.

_Cenosphæra acanthica_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 86, Taf.

i. fig. 3.

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.

_Acanthosphæra haliphormis_, Ehrenberg, 1861, Abhandl. d. k. Akad. d.

Wiss. Berlin, 1872, Taf. ii. fig. 1.

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.

{216}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.

_Rhaphidococcus simplex_, Haeckel, Monogr. d. Radiol., 1862, p. 366,

figs. 5, 6.Taf. xiii.

_Cladococcus simplex_, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.

Wiss. Berlin, p. 800.

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 {217}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).

_Rhaphidosphæra reticulata_, Haeckel, 1881, Prodromus.

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.

{218}_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.

_Heliosphæra actinota_, Haeckel, 1862, Monogr. d. Radiol., p. 352, Taf.

ix. fig. 3.

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.

_Heliosphæra echinoides_, Haeckel, 1862, Monogr. d. Radiol., p. 352, Taf.

ix. fig. 4.

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.

_Heliosphæra elegans_, Haeckel, 1862, Monogr. d. Radiol., p. 353, Taf.

ix. fig. 5.

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).

_Acanthosphæra pectinata_, Haeckel, 1881, Atlas.

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 {219}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, 6_a_).

_Acanthosphæra coronata_, Haeckel, 1881, Atlas.

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. 6_a_); 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, 1_b_); 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,

{220}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.

{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.

The genus _Leptosphæra_, together with the three following genera, forms

the very peculiar and typical small group of #Sphæroidea# which we call the

Diplosphærida (with four genera and twenty-four species); their shell is

composed of two concentric spheres as in the three foregoing genera; but

whilst in these the inner shell is an intracapsular medullary shell and the

outer an extracapsular cortical shell, in the Diplosphærida {244}both

shells are extracapsular or cortical shells, therefore the inner shell of

the latter corresponds to the outer of the former. The inner spherical

shell of all Diplosphærida is composed of very delicate beams and large

pores, which are either regular hexagonal or irregular polygonal (never

roundish). From its surface arise a variable number (twenty to thirty) of

stout long radial spines, which are invariably longer than the shell

diameter (often two to three times as long or more), and of three-sided

prismatic form, the three edges either smooth or serrate, often with three

rows of lateral branches (commonly three to five branches in each row); the

latter are invariably of the same form, concavely curved towards the spine,

and decrease in size towards the distal end. From the three edges of each

main spine in all Diplosphærida, at equal distances from the centre, arise

six very thin, thread-like lateral branches (a pair from each edge) and

connect the spine in a tangential direction with all neighbouring spines.

In this manner the polyhedral outer shell is formed, the meshes of which

therefore are always very large and triangular. Sometimes each of these

primary triangular meshes becomes filled up with a secondary network,

either of regular quadrangular or of irregular polygonal secondary meshes.

Besides the constant twenty to thirty large main spines, in the majority of

Diplosphærida bristle-shaped radial by-spines arise, either from the inner

shell (_Diplosphæra_) or from the outer (_Drymosphæra_), or from both

(_Astrosphæra_). They are absent only in _Leptosphæra_. Commonly the

by-spines are simple, rarely forked or branched. The central capsule in the

Diplosphærida is usually enclosed in the inner shell; often it completely

fills up the latter, or drives out a cæcal protuberance through each mesh;

but these processes rarely unite outside. The average size of the

Diplosphærida, which are all pelagic organisms, is much larger than that of

the other Haliommida.

Subgenus 1. _Leptosphærella_, Haeckel.

_Definition._--Radial spines simple, without lateral branches.

1. _Leptosphæra hexagonalis_, n. sp. (Pl. 19, fig. 2).

Inner shell with regular, hexagonal meshes, and very thin, thread-like

bars; outer shell twice as broad, with simple triangular meshes. Radial

spines with three smooth edges. (Fig. 2 represents the central capsule with

numerous club-shaped saccules, prominent externally through the meshes; in

the centre a large simple spherical nucleus, one-third as broad as the

capsule. The skeleton of this species is identical with that of

_Diplosphæra hexagonalis_, Pl. 19, fig. 3, but has no by-spines.)

_Dimensions._--Diameter of the outer shell 0.3, of the inner 0.15.

_Habitat._--Cosmopolitan; Mediterranean (Corfu), North Atlantic (Canary

Islands), Tropical Pacific, surface.

{245}2. _Leptosphæra serrata_, n. sp.

Inner shell with regular, hexagonal meshes, five to six times as broad as

the bars; outer shell three times as broad, with simple triangular meshes.

Radial spines with three serrated edges (of the same form as the main

spines of _Drymosphæra dendrophora_, Pl. 20, fig. 1).

_Dimensions._--Diameter of the outer shell 0.45, of the inner 0.15.

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

3. _Leptosphæra polygonalis_, n. sp.

Inner shell with irregular, polygonal meshes and very thin thread-like

bars; outer shell twice as broad, with simple triangular meshes. Radial

spines with three smooth edges. (Resembles _Drymosphæra polygonalis_, Pl.

19, fig. 1, but has no by-spines.)

_Dimensions._--Diameter of the outer shell 0.35, inner 0.175.

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

Subgenus 2. _Leptosphæromma_, Haeckel.

_Definition._--Radial spines with three rows of lateral branches (one row

on each edge).

4. _Leptosphæra ciliata_, n. sp.

Inner shell with regular, hexagonal meshes and very thin thread-like bars;

outer shell three times as broad, with simple triangular meshes. Radial

spines with smooth edges and three rows of simple, smooth, curved, lateral

branches (six branches on each edge), similar to those of _Diplosphæra

gracilis_.

_Dimensions._--Diameter of the outer shell 0.6, inner 0.2.

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

5. _Leptosphæra spinosa_, Haeckel.

_Diplosphæra spinosa_, R. Hertwig, 1879, Organismus d. Radiol., p. 40,

Taf. v. fig. 2.

Inner shell with regular, hexagonal meshes, five times as broad as the

bars; outer shell three times as broad, with simple triangular meshes.

Radial spines with three densely serrated edges, and with three rows of

serrated, simple, curved, lateral branches (three branches on each edge).

Differs from the preceding in the thicker bars and the elegantly

denticulated spines and branches.

_Dimensions._--Diameter of the outer shell 0.66, inner 0.22.

_Habitat._--Mediterranean (Messina), R. Hertwig.

6. _Leptosphæra stellata_, n. sp.

Inner shell with regular, hexagonal meshes, six times as broad as the bars,

each bar crossed by a transverse tangential rod, so that each mesh

represents an elegant six-rayed star (as {246}in _Astrosphæra stellata_,

Pl. 19, fig. 5, but without radial by-spines); outer shell twice as broad,

with simple triangular meshes. Radial spines with serrated edges and three

rows of simple lateral branches (four branches on each edge).

_Dimensions._--Diameter of the outer shell 0.44, inner 0.22.

_Habitat._--Tropical Atlantic (Ascension Island), Station 343, surface.

7. _Leptosphæra reticulum_, n. sp.

Inner shell with irregular, polygonal meshes and very thin thread-like

bars; outer shell four times as broad, also with irregular, polygonal

meshes, the sides of the triangular main meshes being connected by

irregular lateral ramules, forming an extremely delicate reticulum.

_Dimensions._--Diameter of the outer shell 0.64, inner 0.16.

_Habitat._--South Pacific, Station 291, surface.

Genus 98. _Diplosphæra_,[133] Haeckel, 1860, Monatsber. d. k. preuss. Akad.

d. Wiss. Berlin, p. 804.

_Definition._--#Astrosphærida# with two extracapsular cortical shells,

connected by long, prismatic, radial spines; inner shell with thin radial

by-spines.

The genus _Diplosphæra_ differs from its ancestral form _Leptosphæra_ in

the development of radial by-spines on the surface of the inner shell, the

outer shell being smooth.

Subgenus 1. _Diplosphærella_, Haeckel.

_Definition._--Radial main spines simple, without lateral branches.

1. _Diplosphæra hexagonalis_, n. sp. (Pl. 19, fig. 3).

Inner shell with regular, hexagonal meshes and very thin thread-like bars;

at each nodal-point one bristle-shaped by-spine; outer shell twice as

broad, with simple triangular meshes. Radial spines with three smooth

edges. (The radially striped central capsule, enclosed in the inner shell,

envelops a large central nucleus one-third its size, fig. 3.)

_Dimensions._--Diameter of the outer shell 0.36, inner 0.18.

_Habitat._--Central Pacific, Stations 265 to 274, surface.

2. _Diplosphæra ornata_, n. sp.

Inner shell with regular, hexagonal meshes, four times as broad as the

bars; outer shell three times as broad, with simple triangular meshes.

Radial main spines as well as the bars of both {247}shells very elegantly

denticulated; radial by-spines (very numerous in the surface of the inner

shell) smooth.

_Dimensions._--Diameter of the outer shell 0.7, inner 0.24.

_Habitat._--Indian Ocean, Madagascar, surface, Rabbe.

3. _Diplosphæra dictyota_, n. sp.

Inner shell with regular, hexagonal meshes, six times as broad as the bars;

at each nodal-point one radial by-spine; outer shell two and a half times

as broad, with very delicate square meshes, separated by thread-like bars

which arise from the sides of the triangular main meshes. Radial main

spines with three serrated edges. (Differs from the similar _Diplosphæra

gracilis_ in the simple main spines, with delicate dentition of the edges.)

_Dimensions._--Diameter of the outer shell 0.5, inner 0.2.

_Habitat._--North Atlantic, Canary Islands, surface.

4. _Diplosphæra polygonalis_, n. sp.

Inner shell with irregular, polygonal meshes and very thin thread-like

bars, covered with very numerous bristle-shaped by-spines; outer shell

twice as broad, with simple triangular meshes. Radial main spines with

three smooth edges.

_Dimensions._--Diameter of the outer shell 0.44, inner 0.22.

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

Subgenus 2. _Diplosphæromma_, Haeckel.

_Definition._--Radial main spines with three rows of lateral branches (one

row on each edge).

5. _Diplosphæra gracilis_, Haeckel.

_Diplosphæra gracilis_, Haeckel, 1862, Monogr. d. Radiol., p. 354, Taf.

x. fig. 1.

Inner shell with regular, hexagonal meshes and very thin bars; at each

nodal-point one simple bristle-shaped radial by-spine; outer shell twice as

broad, with very delicate square meshes, separated by thread-like bars

which arise from the sides of the triangular main meshes. Radial spines

with smooth edges and with three rows of simple curved lateral branches

(four to six branches on each edge).

_Dimensions._--Diameter of the outer shell 0.54, inner 0.27.

_Habitat._--Mediterranean (Messina).

6. _Diplosphæra denticulata_, n. sp.

Inner shell with regular, hexagonal meshes, four times as broad as the

bars; at each nodal-point is a simple bristle-shaped by-spine; outer shell

three times as broad, with simple triangular meshes. {248}Radial spines

very strong, with dentated edges and with three rows of lateral branches

(six dentated curved branches on each edge).

_Dimensions._--Diameter of the outer shell 0.4, inner 0.13.

_Habitat._--North Atlantic, Azores, surface.

7. _Diplosphæra reticulata_, n. sp.

Inner shell with regular, hexagonal meshes, five times as broad as the

bars, which are densely covered with very numerous, simple bristle-shaped

by-spines; outer shell four times as broad, with very numerous small

irregular polygonal meshes, forming a very delicate network, and filling

out the large triangular main meshes. Radial spines with three serrated

edges and three rows of short curved branches (four to five branches on

each edge).

_Dimensions._--Diameter of the outer shell 0.6, inner 0.15.

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

Murray.

8. _Diplosphæra triglochin_, n. sp.

Inner shell with irregular, polygonal meshes and very thin thread-like

bars; outer shell three times as broad, with similar irregular polygonal

meshes, filling out the large triangular main meshes. Radial spines with

three serrated edges, each of which bears one single large lateral branch,

concavely curved towards the distal end. By-spines of the inner shell very

numerous.

_Dimensions._--Diameter of the outer shell 0.5, inner 0.17.

_Habitat._--Central Pacific, Station 264, surface.

Genus 99. _Drymosphæra_,[134] Haeckel, 1881, Prodromus, p. 452.

_Definition._--#Astrosphærida# with two extracapsular cortical shells,

connected by long prismatic, radial spines; outer shell with thin radial

by-spines.

The genus _Drymosphæra_ differs from its ancestral form _Leptosphæra_ in

the development of radial by-spines on the surface of the outer shell, the

inner shell being smooth.

Subgenus 1. _Drymosphærella_, Haeckel.

_Definition._--Radial by-spines simple, not branched (main spines simple).

1. _Drymosphæra hexagonalis_, n. sp.

Inner shell with regular, hexagonal meshes and very thin thread-like bars;

outer shell twice as broad, with simple triangular meshes and thin

thread-like bars, which bear very numerous, {249}bristle-shaped radial

by-spines. Radial main spines with three smooth edges. (Differs from the

first species of the other three genera of Diplosphærida in the presence of

by-spines on the outer, and their absence on the inner shell.)

_Dimensions._--Diameter of the outer shell 0.32, inner 0.16.

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

2. _Drymosphæra polygonalis_, n. sp. (Pl. 19, fig. 1).

_Diplosphæra polygonalis_, Haeckel, 1879, Atlas.

Inner shell with irregular, polygonal meshes and very thin thread-like

bars; outer shell one and a half times as broad, with simple triangular

meshes and thicker bars, which bear numerous bristle-shaped radial

by-spines (in the figure the majority of these are broken off). Radial main

spines with three smooth edges. (Similar to _Leptosphæra polygonalis_ and

_Diplosphæra polygonalis_, but differs from both in the presence of

by-spines on the outer, and their absence on the inner shell.)

_Dimensions._--Diameter of the outer shell 0.33, inner 0.22.

_Habitat._--North Pacific, Station 236 south of Japan, surface.

Subgenus 2. _Drymosphæromma_, Haeckel.

_Definition._--Radial by-spines forked or branched (main spines simple).

3. _Drymosphæra furcata_, n. sp.

Inner shell with irregular, polygonal meshes and thin bars, the former five

times as broad as the latter; outer shell two and a half times as broad,

with simple triangular meshes and smooth bars, bearing numerous long smooth

bristle-shaped by-spines, which in the distal half are forked. Radial main

spines with three smooth edges.

_Dimensions._--Diameter of the outer shell 0.4, inner 0.16.

_Habitat._--Indian Ocean, Ceylon, surface, Haeckel.

4. _Drymosphæra cladophora_, n. sp.

Inner shell with irregular, polygonal meshes, three to six times as broad

as the smooth bars; outer shell twice as broad, with simple triangular

meshes and very thin smooth bars, bearing numerous curved, irregularly

branched, smooth by-spines. Radial main spines with three serrated edges.

_Dimensions._--Diameter of the outer shell 0.4, inner 0.2.

_Habitat._--Central Pacific, Station 276, surface.

5. _Drymosphæra dendrophora_, n. sp. (Pl. 20, figs. 1, 1_a_, 1_b_).

Inner shell with irregular, polygonal meshes and very thin thread-like

bars; outer shell one and a half times as broad, with simple triangular

meshes and thicker bars, which bear a forest of {250}very numerous,

repeatedly dichotomous or irregularly branched, curved by-spines, longer

than the diameter of the outer shell. Radial main spines with three

dentated edges. All parts of the skeleton, the net bars as well as the

radial beams and spines, are very elegantly denticulated (fig. 1_b_). The

central capsule (fig. 1_a_) completely distends the inner shell and forces

out protuberances through all its pores; in its centre lies a nucleus

one-third its size.

_Dimensions._--Diameter of the outer shell 0.25, inner 0.16.

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

Genus 100. _Astrosphæra_,[135] n. gen.

_Definition._--#Astrosphærida# with two extracapsular cortical shells,

connected by long, prismatic, radial spines; inner and outer shell with

thin radial by-spines.

The genus _Astrosphæra_ differs from its ancestral form, _Leptosphæra_, in

the development of radial by-spines on the surface of both shells.

Subgenus 1. _Astrosphærella_, Haeckel.

_Definition._--Radial main spines simple without lateral branches.

1. _Astrosphæra hexagonalis_, n. sp. (Pl. 19, fig. 4).

Inner shell with regular, hexagonal meshes and very thin bars, having a

bristle-shaped, short radial by-spine in each hexagon-corner; outer shell

twice as broad, with simple triangular meshes and thicker bars, bearing one

row of simple bristle-shaped, curved, radial by-spines. Radial main spines

with three smooth edges.

_Dimensions._--Diameter of the outer shell 0.32, inner 0.16.

_Habitat._--South Pacific (West Patagonia), Station 302, surface.

2. _Astrosphæra splendens_, n. sp.

Inner shell with regular, hexagonal meshes, four times as broad as the

bars, and covered with numerous curved, long, bristle-shaped by-spines;

outer shell three times as broad, with simple triangular meshes and thin

bars, bearing a row of very long, curved, bristle-shaped by-spines. Radial

main spines with three dentated edges. All parts of the skeleton elegantly

denticulated, as in _Drymosphæra dendrophora_ (Pl. 20, fig. 1).

_Dimensions._--Diameter of outer shell 0.7, inner 0.24.

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

{251}Subgenus 2. _Astrosphæromma_.

_Definition._--Radial main spines with three rows of lateral branches (one

row on each edge).

3. _Astrosphæra sideræa_, n. sp.

Inner shell with regular, hexagonal meshes, six times as broad as the bars,

and covered with numerous short bristle-shaped by-spines; outer shell four

times as broad, with simple triangular meshes, and rows of long

bristle-shaped by-spines arising from the bars. Radial main spines with

three serrated edges and three rows of lateral branches (four branches on

each edge).

_Dimensions._--Diameter of the outer shell 0.6, inner 0.15.

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

4. _Astrosphæra stellata_, n. sp. (Pl. 19, fig. 5).

_Diplosphæra stellata_, Haeckel, 1881, Prodrom. et Atlas.

Inner shell with regular, hexagonal, six-rayed meshes, each bar being

crossed by a transverse tangential rod, at each nodal-point a long

bristle-shaped by-spine; outer shell three times as broad, with simple

triangular meshes and denticulated thin bars, bearing a row of

bristle-shaped radial by-spines. Radial main spines in the proximal half

with three serrated edges, in the distal half with three rows of curved

lateral branches (five branches on each edge).

_Dimensions._--Diameter of the outer shell 0.6, inner 0.2.

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

Subfamily ACTINOMMIDA,[136] Haeckel, 1862, Monogr. d. Radiol., p. 440

(_sensu emendato_).

_Definition._--#Astrosphærida# with three concentric, spherical,

lattice-shells, united by radial beams.

Genus 101. _Actinomma_,[137] Haeckel, 1862, Monogr. d. Radiol., p. 440.

_Definition._--#Astrosphærida# with three concentric lattice-spheres and

numerous simple radial spines of one kind.

The genus _Actinomma_ is here restricted to those #Sphæroidea# which

combine the possession of three concentric lattice-shells with numerous

radial spines on the surface; the spines are all simple, being of one and

the same kind. Commonly two of the three shells are intracapsular medullary

shells, connected by radial beams (piercing {252}the central capsule) with

the outer, extracapsular, cortical shell. But in some species only one

medullary shell is enclosed in the central capsule, whilst both other

shells lie outside it. In such case the distance between these two cortical

shells is much smaller than their distance from the simple internal

medullary shell. These forms correspond more to aculeate _Rhodosphæræ_,

whilst the others resemble aculeate _Thecosphæræ_.

Subgenus 1. _Actinommantha_, Haeckel.

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

and similar form; spines on the entire surface (commonly one spine at each

nodal-point).

1. _Actinomma hexagonium_, n. sp.

Cortical shell, as well as both medullary shells, very thin walled, with

regular, hexagonal pores and thread-like bars between them. Pores of the

outer shell twice as broad as those of the middle, and three times as broad

as those of the inner shells. Radial proportion of the three spheres =

1 : 3 : 9; about twenty thin radial beams between them. At each nodal-point

of the surface arises one bristle-shaped radial spine, half as long as the

radius.

_Dimensions._--Diameter of the outer shell 0.22, middle 0.07, inner 0.025;

meshes of the cortical shell 0.01; length of the spines 0.05.

_Habitat._--Central Pacific, Stations 270 to 274, surface.

2. _Actinomma facetum_, n. sp.

Cortical shell thick walled, with regular, circular, hexagonally framed

pores, three times as broad as the bars. Pores of both medullary shells

regular, circular. Radial proportion of the three spheres = 1 : 2 : 4;

about forty thin radial beams between them. At each nodal-point of the

surface arises one short, three-sided pyramidal, radial spine, about

one-third as long as the radius.

_Dimensions._--Diameter of the outer shell 0.16, middle 0.08, inner 0.04;

cortical pores 0.012, bars 0.004; length of the spines 0.03, basal breadth

0.015.

_Habitat._--North Pacific, Station 253, depth 3125 fathoms.

3. _Actinomma anthomma_, n. sp.

Cortical shell thick walled, with regular, six-lobed pores, twice as broad

as the bars. At each nodal-point of the surface is one short conical radial

spine, as long as the diameter of the pores; one corresponding to each

lobe, and there is therefore around each pore a regular corona of six

spines, as in _Haliomma lirianthus_ (Pl. 28, fig. 1_b_). Both medullary

shells with simple, circular, regular pores. Radial proportion of the three

spheres = 1 : 2.5 : 7; radial beams between them only six, opposite in

pairs in the three dimensive axes.

{253}_Dimensions._--Diameter of the outer shell 0.2, middle 0.075, inner

0.003; cortical pores 0.01, bars 0.005; length of the spines 0.01.

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

4. _Actinomma castanomma_, n. sp.

Cortical shell as well as both medullary shells thick walled, with regular,

circular pores, twice as broad as the bars; between them at each

nodal-point one bristle-shaped radial spine, one-third as long as the

radius, with conical base. Radial proportion of the three spheres =

2 : 3 : 8; only six radial beams between them (opposed in pairs in the

three dimensive axes).

_Dimensions._--Diameter of the outer shell 0.15, middle 0.06, inner 0.04;

cortical pores 0.008, bars 0.004; length of the spines 0.025.

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

5. _Actinomma entactinia_, Stöhr.

_Actinomma entactinia_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 93, Taf.

ii. fig. 12.

Cortical shell as well as both medullary shells thick walled, with regular,

circular pores, of the same breadth as the bars. Radial proportion of the

three spheres = 1 : 3 : 8; radial beams between them very numerous (thirty

to fifty or more?). Entire surface covered with short thick conical

spines, only one-fifth as long as the radius.

_Dimensions._--Diameter of the outer shell 0.16, middle 0.06, inner 0.02;

cortical pores and bars 0.007; length of the spines 0.015.

_Habitat._--Fossil in the Tertiary rocks of Sicily, Grotte, Caltanisetta.

Subgenus 2. _Actinommetta_, Haeckel.

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

similar form; spines not over the entire surface, but scattered at

intervals (their number smaller than that of the nodal-points).

6. _Actinomma japonicum_, n. sp.

Cortical shell thick walled, with regular, circular, hexagonally framed

pores, three times as broad as the bars. Both medullary shells with simple,

circular, regular pores, of the same breadth as the bars. Radial proportion

of the three spheres = 2 : 5 : 9; radial beams between them twenty,

prolonged outside into twenty symmetrically disposed, three-sided pyramidal

spines, as long as the radius.

_Dimensions._--Diameter of the outer shell 0.18, middle 0.1, inner 0.04;

cortical pores 0.01, bars 0.003; length of the spines 0.1, basal breadth

0.012.

_Habitat._--North Pacific, Station 240, east of Japan, surface.

{254}7. _Actinomma denticulatum_, n. sp. (Pl. 29, fig. 3).

Cortical shell thick walled, with regular, circular, double-edged pores,

twice as broad as the bars. Forty to fifty radial spines, three-sided

pyramidal, half as long as the radius, with three elegantly denticulated

edges. Radial proportion of the three spheres = 1 : 2 : 5. (Differs from

_Haliomma denticulatum_ only in the double medullary shell and larger

size.)

_Dimensions._--Diameter of the outer shell 0.14, middle 0.06, inner 0.03;

cortical pores 0.01, bars 0.005; length of the spines 0.04, basal breadth

0.01.

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

8. _Actinomma trinacrium_, Haeckel.

_Actinomma trinacrium_, Haeckel, 1862, Monogr. d. Radiol., p. 441, Taf.

xxiv. figs. 6-8.

_Haliomma trinacrium_, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.

Wiss. Berlin, p. 815.

Cortical shell as well as both medullary shells thin walled, with

subregular, circular pores, twice as broad as the bars. Radial proportion

of the three spheres = 1 : 3 : 9; radial beams between them twenty,

prolonged outside into strong, three-sided pyramidal spines, as long as the

radius; between them, on the surface, numerous similar spines. Sometimes

the latter remain smaller, the pores more irregular, and then this species

corresponds to _Echinomma trinacrium_.

_Dimensions._--Diameter of the outer shell 0.09, middle 0.03, inner 0.01;

cortical pores 0.008, bars 0.004; length of the spines 0.04, basal breadth

0.01.

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

9. _Actinomma pachyderma_, n. sp. (Pl. 29, figs. 4, 5).

Cortical shell very thick walled, with regular, circular, double-edged

pores, twice as broad as the bars. Both medullary shells with simple,

small, circular pores, of the same breadth as the bars. Radial proportion

of the three spheres = 1 : 2 : 4; radial spines about twenty, conical,

shorter than the radius, prolonged inside into twenty very thin connecting

beams (fig. 4).

_Dimensions._--Diameter of the outer shell 0.08, middle 0.04, inner 0.02;

cortical pores 0.01; bars 0.005; length of the spines 0.03, basal breadth

0.01.

_Habitat._--South Pacific, Station 297, depth 1775 fathoms.

Subgenus 3. _Actinommilla_, Haeckel.

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

form; spines over the entire surface (commonly one spine at each

nodal-point).

10. _Actinomma spinigerum_, Stöhr.

_Actinomma spinigerum_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 92, Taf.

ii. fig. 10.

Cortical shell thick walled, with irregular, roundish, or subcircular

pores, twice to four times as broad as the bars. Radial proportion of the

three spheres = 1 : 3 : 8; between them eight (?) {255}connecting radial

beams. Entire surface densely covered with small conical spines, not larger

than the pores.

_Dimensions._--Diameter of the outer shell 0.17, middle 0.07, inner 0.023;

cortical pores 0.006 to 0.012, bars 0.003; length of the spines 0.01.

_Habitat._--Fossil in Tertiary rocks of Sicily, Grotte, Stöhr.

11. _Actinomma hirsutum_, n. sp.

Cortical shell thick walled, with irregular, roundish pores, about the same

breadth as the bars. Radial proportion of the three spheres = 1 : 2 : 8;

between them numerous (twenty to thirty or more) cylindrical connecting

beams. Entire surface densely covered with innumerable small bristle-shaped

spines, as long as the diameter of the inner shell.

_Dimensions._--Diameter of the outer shell 0.25, middle 0.06, inner 0.03;

cortical pores and bars 0.004 to 0.008; length of the spines 0.03.

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

Subgenus 4. _Actinommura_, Haeckel.

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

form; spines not over the entire surface, but scattered at intervals (their

number smaller than that of the nodal-points).

12. _Actinomma capillaceum_, n. sp. (Pl. 29, fig. 6).

Cortical shell very thin walled, with irregular, polygonal meshes (sixteen

to eighteen on the radius), three to six times as broad as the bars. Both

medullary shells with smaller pores of the same structure. Radial

proportion of the three spheres = 1 : 2.5 : 7; radial connecting beams

between them very thin and numerous (one hundred and twenty to one hundred

and fifty or more), each prolonged outside into a short three-sided

pyramidal spine, as long as the radius of the inner shell. (Similar to

_Haliomma capillaceum_.)

_Dimensions._--Diameter of the outer shell 0.27, middle 0.1, inner 0.04;

cortical pores 0.01 to 0.02, bars 0.003; length of the spines 0.02, basal

breadth 0.005.

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

13. _Actinomma arcadophorum_, n. sp. (Pl. 29, figs. 7, 8).

Cortical shell very thin walled, with irregular, polygonal meshes, ten to

twenty times as broad as the bars; twelve to sixteen on the radius. Both

medullary shells with similar delicate network. Radial proportion of the

three spheres = 1 : 2 : 6; numerous thin radial beams (forty to eighty or

more) connect both medullary shells and alternate with other beams, which

arise from arcade-shaped {256}protuberances of the outer medullary shell,

and connect it with the cortical shell. Outer prolongations of these form

the bristle-shaped spines of the surface.

_Dimensions._--Diameter of the outer shell 0.22, middle 0.09, inner 0.04;

cortical pores 0.01 to 0.02, bars 0.001 to 0.002; length of the radial

spines 0.2.

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

14. _Actinomma schwageri_, Stöhr.

_Actinomma schwageri_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 92, Taf.

ii. fig. 9_a_, _b_.

Cortical shell thick walled, with irregular, large, polygonal meshes, five

to twelve times as broad as the bars; six to eight on the radius. Both

medullary shells with very small, circular, regular pores. Radial

proportion of the three spheres = 1 : 2 : 9; connecting radial beams

between them nine, prolonged outside into nine short stout, three-sided

pyramidal spines, as long as the diameter of the inner shell.

_Dimensions._--Diameter of the outer shell 0.17, middle 0.04, inner 0.02;

cortical pores 0.01 to 0.03, bars 0.006 and less; length of the spines

0.02, basal breadth 0.01.

_Habitat._--Fossil in Tertiary rocks of Sicily, Grotte, Stöhr.

15. _Actinomma dodecomma_, n. sp.

Cortical shell thin walled, with irregular, roundish pores, three to six

times as broad as the bars. Both medullary shells with regular, circular

pores, twice as broad as the bars. Radial proportion of the three shells =

1 : 2.5 : 7; connecting radial beams between them twelve, regularly

disposed, prolonged outside into twelve strong, three-sided pyramidal

spines, as long as the radius.

_Dimensions._--Diameter of the outer shell 0.14, middle 0.05, inner 0.02;

cortical pores 0.008 to 0.018, bars 0.003; length of the spines 0.08,

breadth 0.02.

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

16. _Actinomma pachycapsa_, n. sp.

Cortical shell very thick walled, with irregular, roundish pores, twice to

four times as broad as the bars; twelve to sixteen on the radius. Radial

proportion of the three spheres = 1 : 3 : 12. Both medullary shells of

similar irregular structure, connected with the cortical shell by twelve

regularly disposed radial beams, which are prolonged outside into twelve

short stout conical spines, as long as the diameter of the middle shell.

_Dimensions._--Diameter of the outer shell 0.25, middle 0.06, inner 0.02;

cortical pores 0.006 to 0.012, bars 0.003; length of the spines 0.05,

breadth 0.02.

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

17. _Actinomma giganteum_, n. sp.

Cortical shell thick walled, little larger than the outer medullary shell,

whilst the inner is only one-tenth as large. Pores of all three shells

irregular, roundish, or subcircular, twice to three times {257}as broad as

the bars, on an average twice as large in the outer and middle as in the

inner shell. Sixty to eighty short conical radial spines on the surface,

about as long as the diameter of the inner shell, and one-fourth as broad

at the base. Radial proportion of the three spheres = 1 : 9 : 10.

_Dimensions._--Diameter of the outer shell 0.4 to 0.5, middle 0.35 to 0.45,

inner 0.05 to 0.06.

_Habitat._--Fossil in Barbados.

Genus 102. _Echinomma_,[138] Haeckel, 1881, Prodromus, p. 453.

_Definition._--#Astrosphærida# with three concentric lattice-spheres and

numerous simple radial spines of two different kinds; larger main spines

and smaller by-spines.

The genus _Echinomma_, differs from its ancestral form, _Actinomma_, in the

differentiation of the radial spines. Whilst a large number of small

by-spines cover the entire surface, a smaller number of large main spines

are scattered over it, or limited to certain regularly distributed points.

It represents _Heliosoma_ among the Haliommida.

Subgenus 1. _Echinommetta_, Haeckel.

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

and similar form.

1. _Echinomma echinidium_, n. sp.

Cortical shell thin walled, with regular, hexagonal pores, four times as

broad as the bars; ten to twelve on the radius. Both medullary shells with

regular, circular pores, twice as broad as the bars. Radial proportion of

the three spheres = 1 : 2 : 5. Surface covered with short bristle-shaped

by-spines (one in every hexagon-corner); twenty main spines regularly

disposed, three-sided pyramidal, as long as the diameter of the inner

shell.

_Dimensions._--Diameter of the outer shell 0.1, middle 0.045, inner 0.02;

cortical pores 0.008, bars 0.002; length of the main spines 0.02, breadth

0.01.

_Habitat._--South Pacific, Station 295, surface.

2. _Echinomma cidaris_, n. sp.

Cortical shell thin walled, with regular, circular, hexagonally framed

pores, twice as broad as the bars; six to eight on the radius. Both

medullary shells with simple, circular pores. Radial proportion of the

three spheres = 1 : 2 : 6. Surface covered with short bristle-shaped

by-spines, half as long as the forty to fifty main spines, which are

three-sided pyramidal, and reach the radius of the shell.

_Dimensions._--Diameter of the outer shell 0.18, middle 0.06, inner 0.03;

cortical pores 0.01, bars 0.005; length of the main spines 0.08, basal

breadth 0.015.

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

{258}3. _Echinomma aculeatum_, Haeckel.

_Actinomma aculeatum_, Stöhr, 1880 Palæontogr., vol. xxvi. p. 92, Taf.

ii. fig. 11.