Chapter XI: Literature and History (8)

Surface of the shell smooth. Radial proportion of the four spheres = 1 : 2 : 8 : 9. Two medullary shells inside the central capsule, two cortical shells outside it. Interval between the second and third shells the greatest. Pores of all the shells regular, circular, two to four times as broad as the bars. Both polar spines equal, conical, about as long as the axis of the outermost sphere, as broad at the base as the innermost.

_Dimensions._--Diameter of the four spheres--(A) inner medullary shell 0.03, (B) outer medullary shell 0.06, (C) inner cortical shell 0.25, (D) outer cortical shell 0.28; length of the polar spines 0.3, basal breadth 0.03.

_Habitat._--Central Pacific, Station 273, depth 2350 fathoms.

2. _Stylocromyum amphipyramis_, n. sp.

Surface of the shell smooth. Radial proportion of the four spheres = 2 : 3 : 6 : 8. Both medullary shells with regular, circular pores, twice as broad as the bars. Both cortical shells with irregular, roundish, much larger pores, three to six times as broad as the bars. Both polar spines equal or nearly equal, three-sided pyramidal, about as long as the axis of the third shell.

_Dimensions._--Diameter of the four spheres--(A) 0.04, (B) 0.06, (C) 0.12, (D) 0.16; length of the polar spines 0.11, basal breadth 0.02.

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

Genus 55. _Cromyostylus_,[78] Haeckel, 1881, Prodromus, p. 453.

_Definition._--#Stylosphærida# with four concentric lattice-spheres and two free spines of different size or form.

The genus _Cromyostylus_ differs from its ancestral form, _Stylocromyum_, in the differentiation of the two unequal polar spines.

1. _Cromyostylus gladius_, n. sp.

Surface of the shell smooth. Radial proportion of the four spheres = 1 : 3 : 10 : 12. Both medullary shells with regular, circular, simple pores. Inner cortical shell with regular, circular, hexagonally framed pores, twice as broad as the bars. From each hexagon-corner arises a {148}bristle-shaped radial spine, which at the distal end gives off three thread-like branches; by communication of these threads (at equal distances from the centre) the delicate outer medullary shell is formed. The polar spines very different; major spine six-sided pyramidal, longer than the diameter of the shell; minor pommel-shaped, shorter than the radius (similar to _Xiphatractus glyptodon_, Pl. 17, figs. 9, 10, but different in the double spherical cortical shell).

_Dimensions._--Diameter of the four spheres--(A) 0.02, (B) 0.06, (C) 0.2, (D) 0.24; length of the major spine 0.3, of the minor 0.1.

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

Subfamily CARYOSTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 454.

_Definition._--#Stylosphærida# with five or more concentric, spherical lattice-shells.

Genus 56. _Caryostylus_, Haeckel, 1881, Prodromus, p. 454.

_Definition._--#Stylosphærida# with five to six or more concentric lattice-shells and two free opposite spines of equal size and similar form.

The genus _Caryostylus_ differs from its ancestral form, _Stylocromyum_, by the multiplication of the concentric spheres, the number of which amounts to five or six or more. I have only observed one single species of this genus. Some similar forms which in my Prodromus (1881, p. 454) were annexed to it, and disposed in three nearly allied genera (_Caryoxiphus_, _Caryodoras_, _Caryolonche_), have now been proved to belong to other groups, mainly ellipsoidal Druppulida.

1. _Caryostylus hexalepas_, n. sp.

Surface of the spherical shell smooth. Radial proportion of the component six concentric shells = 1 : 2 : 7 : 9 : 12 : 15. Both medullary shells connected only by six radial beams, opposite in pairs in the three dimensive axes. Between second and third shell numerous (twenty regularly disposed?) radial beams. Four cortical shells connected by very numerous (sixty to eighty or more?) short radial beams. Pores of all six shells regular, circular, the size increasing towards the surface, two to three times as broad as the bars. Two opposite polar spines very large, of equal size, three times as long as the shell radius, cylindrical, club-shaped at the thicker distal end. (The whole shell structure is similar to Pl. 15, fig. 2, but the shells are spherical, not ellipsoidal.)

_Dimensions._--Diameter of the six spheres--(A) 0.02, (B) 0.04, (C) 0.15, (D) 0.18, (E) 0.24, (F) 0.3; length of the spines 0.5.

_Habitat._--West Tropical Pacific, Station 225, depth 4475 fathoms.

Subfamily SPONGOSTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 455.

_Definition._--#Stylosphærida# with spherical spongy shell (with or without enclosed latticed medullary shells).

{149}Genus 57. _Spongolonchis_,[79] Haeckel, 1881, Prodromus, p. 455.

_Definition._--#Stylosphærida# with a solid sphere of spongy framework, and with two opposite free radial spines.

The genus _Spongolonchis_ differs from its probable ancestral form, _Styptosphæra_, by the development of two opposite radial spines situated in one axis.

1. _Spongolonchis compacta_, n. sp.

Spongy framework of the spherical shell very compact, with small meshes, three to four times as broad as the bars. Surface rough, but not spiny. Two polar spines pyramidal, only as long as the radius of the shell, one-third as broad at the base.

_Dimensions._--Diameter of the shell 0.2; length of the spines 0.1, basal breadth 0.03.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

2. _Spongolonchis laxa_, n. sp.

Spongy framework loose, with large meshes, ten to twelve times as broad as the bars. Surface spiny. Two polar spines three-sided prismatic, longer than the diameter of the shell (broken off in the observed specimen).

_Dimensions._--Diameter of the shell 0.5; length of the spine 0.6 and more, breadth 0.02.

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

Genus 58. _Spongostylus_,[80] Haeckel, 1881, Prodromus, p. 455.

_Definition._--#Stylosphærida# with spongy spherical cortical shell, enclosing in the centre a simple latticed medullary shell, and with two opposite free radial spines.

The genus _Spongostylus_ may probably be derived from _Spongoplegma_ by development of two opposite radial spines in one axis.

1. _Spongostylus hastatus_, n. sp.

Spongy cortical shell with compact framework, twice as broad as the enclosed medullary shell, the pores of which are regular, circular, twice as broad as the bars. Two polar spines, three times as long as the radius of the shell, in the basal two-thirds cylindrical, in the distal third compressed, two-edged, spear-shaped.

_Dimensions._--Diameter of the cortical shell 0.1, medullary shell 0.05; length of the spines 0.15.

_Habitat._--South Atlantic, Station 335, depth 1425 fathoms.

{150}2. _Spongostylus gladiatus_, Haeckel.

_Stylosphæra holosphæra_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 299, Taf. viii. fig. 14.

Spongy cortical shell with rather compact framework, four times as broad as the enclosed medullary shell, the pores of which are irregular, roundish, three to four times as broad as the bars. Two polar spines sword-shaped, two-edged, as long as the shell diameter.

_Dimensions._--Diameter of the cortical shell 0.24, medullary shell 0.06; length of the spines 0.25.

_Habitat._--Central Pacific, Station 268, depth 2900 fathoms; Philippine Sea, depth 3300 fathoms.

3. _Spongostylus serratus_, n. sp.

Spongy cortical shell with lax framework, ten to twelve times as broad as the enclosed medullary shell, the pores of which are irregular, roundish, once and a half to twice as broad as the bars. Two polar spines longer than the shell diameter (broken off in the observed specimen), three-sided prismatical, with three straight serrated edges.

_Dimensions._--Diameter of the cortical shell 0.5, medullary shell 0.04; length of the spines 0.6 or more.

_Habitat._--South Pacific, Station 285, depth 2375 fathoms.

Genus 59. _Spongostylidium_,[81] Haeckel, 1881, Prodromus, p. 455.

_Definition._--#Stylosphærida# with spongy spherical cortical shell, enclosing two concentric spherical latticed medullary shells, and with two opposite, free radial spines.

The genus _Spongostylidium_ differs from _Spongostylus_ by duplication of the latticed medullary shell, and therefore bears the same relation to it as _Spongodictyon_ to _Spongoplegma_.

1. _Spongostylidium streptacanthum_, n. sp.

Both medullary shells spherical, with small, regular, circular pores, twice as broad as the bars (outer twice as broad as the inner). Spongy cortical shell enclosing it with dense framework, four times as broad as the outer medullary shell. Two polar spines very large, four times as long as the diameter of the outer shell; as broad as the inner medullary shell, with three dentated, spirally contorted edges. (Very similar to the common _Spongosphæra streptacantha_ and to _Hexadoridium streptacanthum_, but with only two opposite spines in one axis.)

_Dimensions._--Diameter of the cortical shell 0.16, of the outer medullary shell 0.04, inner 0.02; length of the spines 0.7 and more, breadth 0.02.

_Habitat._--Indian Ocean, Cocos Islands, Rabbe.

{151}Family VIII. #STAUROSPHÆRIDA#, Haeckel (Pl. 15).

_Staurosphærida_, Haeckel, 1881, Prodromus, p. 449.

_Definition._--#Sphæroidea# with four radial spines on the surface of the spherical shell, forming a regular cross, being opposite in pairs in two axes perpendicular to one another; living solitary (not associated in colonies).

The family #Staurosphærida# is distinguished from the other #Sphæroidea# by the possession of four radial spines, which are opposite in pairs in two perpendicularly crossed axes. By these "two main axes" an equatorial plane is determined, which approximates them to the #Discoidea#. But in the latter the shells as well as the central capsule become more or less flattened, lenticular, or discoidal, whilst in the former they remain spherical. However, some forms of both groups are very similar, and inspection from different sides (and mainly from the margin of the equatorial plane) is required to determine the spherical (not compressed) shell-form of the Staurosphærida. As a rule the species of this family are much rarer, and much less numerous, than those of all the other #Sphæroidea#.

The most simple Staurosphærida are the Staurostylida, with one single spherical lattice-shell. To this ancestral group all other subfamilies can be opposed as "Staurosphærida concentrica," since their carapace is composed of two or more concentric lattice-shells; two in the Staurolonchida, three in the Stauracontida, four in the Staurocromyida, five or more in the Staurocaryida. In all these four subfamilies the concentric shells are simple (not spongy) fenestrated spheres. In a sixth subfamily, in the Staurodorida, the shell is wholly or partially composed of irregular spongy wickerwork, with or without a medullary shell in the centre.

_The Four Radial Spines_ in all Staurosphærida are normally opposed in pairs in two axes perpendicular one to another, and therefore together form a rectangular cross. But in many species besides this normal form individual abnormalities occur, in which the four spines in the equatorial plane are not quite accurately opposed, so that the four angles between them are not right angles, but more or less unequal. More rarely also their position in the equatorial plane is not accurately retained, so that they are placed in two, three, or four different meridian planes, intersecting at very small variable angles.

In the greater part of Staurosphærida all four radial spines are quite equal, and of the same size and form. But in some genera there takes place a more or less considerable differentiation of the four spines, commonly in pairs, so that the two opposite spines of each pair are equal, but the pairs different (_Staurostylus_, _Staurolonchidium_). More rarely also both spines of one pair become unequal, whilst those of the other pair remain equal (_Stauroxiphos_). Very rarely all four spines assume a different size or form.

{152}_Synopsis of the Genera of Staurosphærida._

I. Subfamily {All four spines equal, 60. _Staurosphæra_.
Staurostylida. {
(Shell one single {Four spines different
lattice-sphere.) { in pairs, 61. _Staurostylus_.
{
{One spine larger than the
{ three others, 62. _Stylostaurus_.

II. Subfamily {All four spines {Simple, 63. _Staurolonche_.
Staurolonchida. { equal, {
(Shell with { {Branched, 64. _Staurancistra_.
two concentric {
lattice-spheres.) {Four spines different 65.
{ in pairs, _Staurolonchidium_.
{
{One spine larger than
{ the three others, 66. _Stauroxiphos_.

III. Subfamily }All four spines equal,
Stauracontida. } simple, 67. _Stauracontium_.
(Shell with three }
concentric spheres.) }

IV. Subfamily }All four spines {Simple, 68. _Staurocromyum_.
Staurocromyida. } equal, {
(Shell with four } {Branched, 69. _Cromyostaurus_.
concentric spheres.) }

V. Subfamily }All four spines equal, 70. _Staurocaryum_.
Staurocaryida. }
(Shell with five }
or more concentric }
spheres.) }

VI. Subfamily }Solid spongy sphere
Staurodorida. } without medullary shell, 71. _Staurodoras_.
(Shell a spongy }
sphere.) }

Subfamily STAUROSTYLIDA,[82] Haeckel, Prodromus, 1881, pp. 449, 450.

_Definition._--#Staurosphærida# with one single spherical lattice-shell.

Genus 60. _Staurosphæra_,[83] Haeckel, 1881, Prodromus, p. 450.

_Definition._--#Staurosphærida# with a single lattice-sphere and four crossed equal spines.

The genus _Staurosphæra_ may be regarded as the common ancestral form of this subfamily, since it represents their most simple and primitive form. From the surface of the simple lattice-sphere, enclosing the central capsule, arise four equal, simple, radial spines, opposite in pairs in two diameters, perpendicular one to another. _Staurosphæra_ may be derived phylogenetically either from _Cenosphæra_ by production of the four spines, or from _Hexastylus_ by reduction of two opposite spines.

{153}Subgenus 1. _Staurosphærantha_, Haeckel.

_Definition._--Pores regular, all of nearly equal size and similar form; surface smooth.

1. _Staurosphæra cruciata_, n. sp.

Shell thin walled, smooth, with regular, hexagonal pores, four times as broad as the bars; ten to twelve on the quadrant. Four crossed radial spines three-sided pyramidal, as long as the diameter of the shell, as broad at the base as one pore (very similar to _Hexastylus phænaxonius_, Pl. 21, fig. 3, but with only four spines).

_Dimensions._--Diameter of the shell 0.12, of the pores 0.008, bars 0.002.

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

2. _Staurosphæra christiana_, n. sp.

Shell thick walled, smooth, with regular, circular, hexagonally framed pores, three times as broad as the bars; six to eight on the quadrant. Four crossed spines six-sided pyramidal, as long as the radius, as broad as one mesh.

_Dimensions._--Diameter of the shell 0.13, pores 0.012, bars 0.004.

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

3. _Staurosphæra johannis_, n. sp.

Shell thick walled, smooth, with regular, circular pores, four times as broad as the bars; five to six on the quadrant. Four spines six-sided pyramidal, half as long as the radius, as broad as one mesh.

_Dimensions._--Diameter of the shell 0.15, pores 0.02, bars 0.005.

_Habitat._--North Pacific, Station 241, depth 2300 fathoms.

4. _Staurosphæra pauli_, n. sp.

Shell very thick walled, smooth, with regular, circular, double-edged pores, four times as broad as the bars; eight to ten on the quadrant. Four spines conical, as long as the radius, as broad as one mesh.

_Dimensions._--Diameter of the shell 0.15, pores 0.016, bars 0.004.

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

5. _Staurosphæra petri_, n. sp.

Shell thin walled, smooth, with regular, circular pores, three times as broad as the bars; twenty to twenty-two on the quadrant. Four spines conical, half as long as the radius, as broad as one mesh.

_Dimensions._--Diameter of the shell 0.22, pores 0.006, bars 0.002.

_Habitat._--South Atlantic, Station 325, depth 2650 fathoms; also fossil in Barbados.

{154}6. _Staurosphæra jacobi_, n. sp.

Shell thick walled, smooth, with regular, circular pores, twice as broad as the bars; eleven to twelve on the quadrant. Four spines cylindrical, three times as long as the radius, three times as broad as one mesh.

_Dimensions._--Diameter of the shell 0.1, pores 0.006, bars 0.003.

_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.

7. _Staurosphæra simonis_, n. sp.

_Haliomma_ with four spines, Bury, 1862, Polycystins of Barbados, pl. iv.
fig. 4.

Shell thick walled, smooth, with regular, circular pores, of the same breadth as the bars; eight to ten on the quadrant. Four spines cylindrical, twice as long as the radius, five times as broad as one mesh.

_Dimensions._--Diameter of the sphere 0.1, pores and bars 0.003.

_Habitat._--Fossil in Barbados.

Subgenus 2. _Staurosphærella_, Haeckel.

_Definition._--Pores regular, all of nearly equal size and similar form; surface covered with by-spines or accessory thorns.

8. _Staurosphæra philippi_, n. sp. (Pl. 15, fig. 6).

Shell thin walled, covered with bristle-shaped by-spines, as long as the radius. Pores regular, circular, twice as broad as the bars; six to eight on the quadrant. Four main spines cylindrical, five to ten times as long as the radius, as broad as one mesh.

_Dimensions._--Diameter of the shell 0.08, pores 0.006, bars 0.003.

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

9. _Staurosphæra andreæ_, n. sp.

Shell thick walled, with regular, circular, hexagonally framed pores, three times as broad as the bars; nine to ten on the quadrant. From each hexagon-corner arises a bristle-shaped by-spine, half as long as the radius. Four main spines three-sided pyramidal, with spirally contorted edges, as long as the radius (very similar to _Hexastylus solonis_, Pl. 21, fig. 11, but with only four spines).

_Dimensions._--Diameter of the shell 0.16, pores 0.01, bars 0.003.

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

{155}10. _Staurosphæra thomæ_.

Shell thick walled, with regular, circular pores, twice as broad as the bars; twelve to fourteen on the quadrant; surface covered with short conical by-spines. Four main spines conical, twice as long as the radius, twice as broad as one mesh.

_Dimensions._--Diameter of the sphere 0.2, pores 0.012, bars 0.006.

_Habitat._--South Atlantic, Station 332, depth, 2200 fathoms.

Subgenus 3. _Staurosphærissa_, Haeckel.

_Definition._--Pores irregular, of different size or form; surface smooth.

11. _Staurosphæra judæ_, n. sp.

Shell thin walled, smooth, with irregular, polygonal pores, twice to four times as broad as the bars; six to ten on the quadrant. Four main spines three-sided pyramidal, as long as the radius.

_Dimensions._--Diameter of the sphere 0.15, pores 0.006 to 0.012, bars 0.003.

_Habitat._--Central Pacific, Station 273, depth, 2350 fathoms.

12. _Staurosphæra crassa_, Dunikowski.

_Staurosphæra crassa_, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd.
xlv. p. 27, Taf. v. figs. 52-55.

Shell thick walled, smooth, with irregular, roundish pores, scarcely broader than the bars; eight to ten on the quadrant. Four spines three-sided pyramidal, nearly as long as the shell diameter.

_Dimensions._--Diameter of the sphere 0.19, pores and bars 0.015.

_Habitat._--Fossil in the Alpine Lias (Schafberg near Salzburg, Dunikowski).

13. _Staurosphæra apostolorum_, Haeckel.

? _Cenosphæra megapora_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. iii. fig. 1.

? _Cenosphæra micropora_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 66, Taf. iii. fig. 2.

Shell thin walled, smooth, with large, irregular, roundish pores, twice to six times as broad as the bars; four to six on the quadrant. Four spines conical, very stout, about as long as the shell diameter, often more or less irregularly disposed.

_Dimensions._--Diameter of the sphere 0.12 to 0.2, pores 0.01 to 0.03, bars 0.005.

_Habitat._--Fossil in Barbados.

{156}Subgenus 4. _Staurosphæromma_, Haeckel.

_Definition._--Pores irregular, of different size or form; surface covered with by-spines or accessory thorns.

14. _Staurosphæra bartholomæi_, n. sp.

Shell thin walled, with irregular, polygonal pores, three times as broad as the bars; six to eight on the quadrant; surface covered with short bristle-shaped by-spines. Four main spines three-sided pyramidal, twice as long as the radius.

_Dimensions._--Diameter of the shell 0.14, pores 0.008 to 0.016, bars 0.003 to 0.005.

_Habitat._--South Pacific, Station 285, depth 2375 fathoms.

15. _Staurosphæra thaddæi_, n. sp.

Shell thick walled, with irregular, roundish, polygonally framed pores, twice to three times as broad as the bars; five to seven on the quadrant; surface covered with bristle-shaped spines, half as long as the radius. Four main spines pyramidal, as long as the radius.

_Dimensions._--Diameter of the shell 0.12, pores 006 to 0.012, bars 0.004.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms; also fossil in Barbados.

16. _Staurosphæra matthæi_, n. sp.

Shell thick walled, with irregular, roundish pores, twice to five times as broad as the bars; ten to twelve on the quadrant; surface covered with short conical thorns or by-spines. Four main spines conical, as long as the radius.

_Dimensions._--Diameter of the shell 0.15, pores 0.004 to 0.01, bars 0.002.

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

Genus 61. _Staurostylus_,[84] Haeckel, 1881, Prodromus, p. 450.

_Definition._--#Staurosphærida# with one single lattice-sphere and four crossed spines which are arranged in opposite pairs, one pair opposite being larger than the other.

The genus _Staurostylus_ has been developed from _Staurosphæra_ by differentiation of the four crossed spines in pairs; two opposite spines growing much more strongly than the other two.

1. _Staurostylus græcus_, n. sp.

Shell thick walled, smooth, with regular, circular, hexagonally framed pores, twice as broad as the bars; six to eight on the quadrant. Spines three-sided prismatic, pointed, as broad as {157}one mesh; two opposite larger spines as long as the diameter of the shell, two smaller only as long as the radius.

_Dimensions._--Diameter of the shell 0.15, pores 0.01, bars 0.005; length of the major spines 0.16, minor 0.08.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

2. _Staurostylus latinus_, n. sp.

Shell thin walled, smooth, with regular, circular, double-edged pores, three times as broad as the bars; twelve to fourteen on the quadrant. Spines conical, twice as broad at the base as one mesh; two opposite larger spines as long as the radius of the shell, two smaller only one-third as long.

_Dimensions._--Diameter of the shell 0.24, pores 0.012, bars 0.004; length of the major spines 0.12, minor 0.04.

_Habitat._--South Pacific, Station 295, depth 1500 fathoms.

3. _Staurostylus germanicus_, n. sp.

Shell thick walled, covered with bristle-shaped by-spines, half as long as the radius. Pores regular, circular, hexagonally framed, twice as broad as the bars; eight to ten on the quadrant. From each hexagon-corner arises one short by-spine. Four main spines three-sided pyramidal, as broad at the base as one mesh; two opposite larger spines one and a half times as long as the radius, two smaller two-thirds as long.

_Dimensions._--Diameter of the shell 0.16, pores 0.008, bars 0.004; length of the major spines 0.12, minor 0.08.

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

Genus 62. _Stylostaurus_,[85] 1881, Prodromus, p. 450.

_Definition._--#Staurosphærida# with one single lattice-sphere and four crossed spines, one of which is much larger than the other three.

The genus _Stylostaurus_ differs from the preceding in the extraordinary development of one of the four spines, which is much longer than the other three; these may be equal or different.

1. _Stylostaurus caudatus_, n. sp. (Pl. 13, fig. 7).

Shell thick walled, smooth, with regular, circular, hexagonally framed pores, twice as broad as the bars; five to six on the quadrant. Spines three-sided pyramidal, as broad at the base as {158}one mesh; one of the spines longer than the shell diameter, the opposite spine nearly as long as the shell radius; both lateral spines scarcely one-third as long.

_Dimensions._--Diameter of the shell 0.1, pores 0.01, bars 0.005; length of the major spine 0.14, of the opposite 0.04, of both lateral spines 0.012.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

2. _Stylostaurus gladiatus_, n. sp.

Shell thick walled, smooth, with regular, circular pores, three times as broad as the bars; nine to ten on the quadrant. Spines three-sided prismatic, as broad at the base as one mesh; one of the spines longer than the shell diameter, and much larger than the other three, which are nearly equal (half as long as the radius).

_Dimensions._--Diameter of the shell 0.2, pores 0.015, bars 0.005; length of the major spine 0.25, of the three others 0.005.

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

Subfamily STAUROLONCHIDA,[86] Haeckel, 1881, Prodromus, pp. 449, 451.

_Definition._--#Staurosphærida# with two concentric spherical lattice-shells.

Genus 63. _Staurolonche_,[87] Haeckel, 1881, Prodromus, p. 451.

_Definition._--#Staurosphærida# with two concentric lattice-spheres and four crossed, equal, simple spines.

The genus _Staurolonche_ may be derived either from _Staurosphæra_ by the duplication of the lattice-sphere, or from _Carposphæra_ by the production of four crossed radial spines, lying in one meridional plane, or from _Hexalonche_ by the reduction of two opposite spines.

Subgenus 1. _Staurolonchantha_, Haeckel.

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

1. _Staurolonche hexagona_, n. sp.

_Haliomma hexagonum_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvb., Bd. iv.
fig. 17.

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

Cortical shell thin walled, smooth, three times as broad as the medullary shell, with regular, hexagonal pores, four times as broad as the bars; seven to eight on the quadrant. Four spines three-sided pyramidal, somewhat longer than the radius, as broad at the base as one mesh.

{159}_Dimensions._--Diameter of the outer shell 0.12, inner 0.04; cortical pores 0.012, bars 0.003; length of the spines 0.08.

_Habitat._--North Atlantic, Station 64, depth 2700 fathoms.

2. _Staurolonche spinozæ_, n. sp.

Cortical shell thick walled, smooth, twice as broad as the medullary shell, with regular, circular, hexagonally framed pores, three times as broad as the bars; five to six on the quadrant. Four spines three-sided pyramidal, half as long as the radius, as broad at the base as one mesh.

_Dimensions._--Diameter of the outer shell 0.16, inner 0.08; cortical pores 0.012, bars 0.004; length of the spines 0.04.

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

3. _Staurolonche aperta_, Haeckel.

_Haliomma apertum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 74, Taf. xxviii. fig. 5.

Cortical shell thin walled, smooth, three times as broad as the medullary shell; pores regular, circular, five times as broad as the bars; four to five on the quadrant. Four spines conical, as long as the radius, as broad as one mesh.

_Dimensions._--Diameter of the outer shell 0.1, inner 0.03; cortical pores 0.015, bars 0.003; length of the spines 0.05.

_Habitat._--Fossil in Barbados.

4. _Staurolonche brunonis_, n. sp.

Cortical shell thick walled, smooth, twice as broad as the medullary shell, with regular, circular pores, three times as broad as the bars; eight to ten on the quadrant. Four spines cylindro-conical, longer than the diameter, twice as broad as one mesh.

_Dimensions._--Diameter of the outer shell 0.08, inner 0.04; cortical pores 0.006, bars 0.002; length of the spines 0.12.

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

5. _Staurolonche pertusa_, n. sp. (Pl. 15, figs. 5, 5_a_).

Cortical shell thin walled, smooth, three times as broad as the medullary shell, with regular, circular pores, three times as broad as the bars; eight to ten on the quadrant. Pores of the medullary shell only one-third as large, also circular. Four spines three-sided prismatic, three times as long as the radius; each of their three thin wings perforated by a single row of small pores.

_Dimensions._--Diameter of the outer shell 0.1, inner 0.033; cortical pores 0.01, bars 0.003; length of the spines 0.15.

_Habitat._--North Atlantic, Station 353, surface.

{160}Subgenus 2. _Staurolonchella_, Haeckel.

_Definition._--Pores of the cortical shell regular, and of nearly equal size and similar form; surface covered with by-spines or thorns.

6. _Staurolonche straussii_, n. sp.

Cortical shell thin walled, four times as broad as the medullary shell, and covered with numerous bristle-shaped by-spines, half as long as the radius. Pores regular, circular, hexagonally framed, twice as broad as the bars; six to eight on the radius. On each hexagonal frame twelve by-spines (six at the corners, six in the middle between them). Four main spines six-sided pyramidal, about as long as the radius, twice as broad as one mesh.

_Dimensions._--Diameter of the outer shell 0.16, inner 0.04; cortical pores 0.016, bars 0.008; length of the spines 0.1.

_Habitat._--West Tropical Pacific, Station 225, depth 4475 fathoms.

7. _Staurolonche feuerbachii_, n. sp.

Cortical shell thick walled, five times as broad as the medullary shell, and covered with short conical by-spines. Pores regular, circular, twice as broad as the bars; twenty to twenty-two on the quadrant. Four main spines three-sided prismatic, with pyramidal apex, two to three times as long as the radius, twice as broad as one mesh.

_Dimensions._--Diameter of the outer shell 0.27, of the inner 0.055; cortical pores 0.008, bars 0.004; length of the spines 0.3 to 0.4.

_Habitat._--Fossil in Barbados.

8. _Staurolonche moleschottii_, n. sp.

Cortical shell thick walled, three times as broad as the medullary shell, and covered with short conical by-spines. Pores regular, circular, of the same breadth as the bars; fourteen to sixteen on the quadrant. Four main spines conical, as long as the radius, three times as broad at the base as one mesh.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; cortical pores and bars 0.004; length of the spines 0.08.

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

Subgenus 3. _Staurolonchissa_, Haeckel.

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

9. _Staurolonche holbachii_, n. sp.

Cortical shell thin walled, with smooth surface, three times as broad as the medullary shell. Pores irregular, polygonal, twice to four times as broad as the bars. Four main spines three-sided prismatic, longer than the shell diameter.

{161}_Dimensions._--Diameter of the outer shell 0.12, inner 0.04; cortical pores 0.006 to 0.012, bars 0.003; length of the spines 0.15.

_Habitat._--South Pacific, Station 295, depth 1500 fathoms.

10. _Staurolonche gassendii_, n. sp.

Cortical shell thick walled, with smooth surface, four times as broad as the medullary shell. Pores irregular, roundish, three to five times as broad as the bars. Four main spines conical, as long as the radius.

_Dimensions._--Diameter of the outer shell 0.2, inner 0.05; cortical pores 0.01 to 0.02, bars 0.004; length of the spines 0.1.

_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.

Subgenus 4. _Staurolonchura_, Haeckel.

_Definition._--Pores of the cortical shell irregular, of different size or form; surface covered with by-spines or thorns.

11. _Staurolonche epicurii_, n. sp.

Cortical shell thick walled, five times as broad as the medullary shell, and covered with numerous bristle-shaped by-spines (half as long as the radius). Pores irregular, roundish, polygonally framed, twice to three times as broad as the bars. Four main spines pyramidal, as long as the radius.

_Dimensions._--Diameter of the outer shell 0.22, inner 0.044; cortical pores 0.02 to 0.04, bars 0.012; length of the spines 0.1.

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

12. _Staurolonche lucretii_, n. sp.

Cortical shell thick-walled, three times as broad as the medullary shell, and covered with numerous short, conical thorns. Pores irregular, roundish, twice to four times as broad as the bars. Four main spines conical, half as long as the radius.

_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; cortical pores 0.015 to 0.03, bars 0.008; length of the spines 0.04.

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

Genus 64. _Staurancistra_,[88] Haeckel, 1881, Prodromus, p. 451.

_Definition._--#Staurosphærida# with two concentric lattice-spheres and four crossed, equal, branched spines.

{162}The genus _Staurancistra_ differs from its ancestral form, _Staurolonche_, in the ramification of the four crossed spines.

1. _Staurancistra quadricuspis_, n. sp.

Cortical shell thin walled, with rough, thorny surface, and irregular, roundish pores, twice to four times as broad as the bars; six to eight on the quadrant. Medullary shell one-third as large, with regular, circular pores; connected with the cortical shell by four crossed radial beams. These are prolonged outside into four strong three-sided prismatic spines, nearly as long as the shell diameter, each having three curved branches below the distal end. (Similar to _Hexancistra quadricuspis_, Pl. 22, fig. 11, but with only four spines.)

_Dimensions._--Diameter of the cortical shell 0.16, of the medullary shell 0.05; pores of the former 0.06 to 0.012, bars 0.003; length of the spines 0.14, breadth 0.012.

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

Genus 65. _Staurolonchidium_,[89] n. gen.

_Definition._--#Staurosphærida# with two concentric lattice-spheres and four crossed simple spines which are disposed in two different pairs, two opposite being larger than the other two.

The genus _Staurolonchidium_ has arisen from _Staurolonche_ by the stronger growth of the two opposite spines, the other two remaining stationary; both spines of each pair equal.

1. _Staurolonchidium artioscelides_, n. sp.

Cortical shell thin walled, with smooth surface, three times as broad as the medullary shell. Pores regular, circular, hexagonally framed, twice as broad as the bars; eight to ten on the quadrant. Four radial spines three-sided pyramidal, as broad as one mesh; two opposite larger spines three times as long as the two smaller, which are about equal to the radius.

_Dimensions._--Diameter of the cortical shell 0.16, medullary shell 0.05; pores of the former 0.012, bars 0.006; length of the major spines 0.24, minor 0.08.

_Habitat._--Central Pacific, Station 265, surface.

2. _Staurolonchidium perspicuum_, Haeckel.

_Haliomma perspicuum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 74, Taf. xxix. fig. 1.

Cortical shell thin walled, covered with small conical by-spines, five times as broad as the medullary shell. Pores regular, circular, eight times as broad as the bars; three to four on the quadrant. Four radial spines three-sided pyramidal, scarcely one-third as broad as one mesh; two opposite larger spines four times as long as the two smaller, which are about equal to half the radius.

{163}_Dimensions._--Diameter of the cortical shell 0.12, medullary shell 0.025; pores of the former 0.03, bars 0.004; length of the major spines 0.12, minor 0.03.

_Habitat._--Fossil in Barbados.

Genus 66. _Stauroxiphos_,[90] n. gen.

_Definition._--#Staurosphærida# with two concentric lattice-spheres and four crossed simple spines, one of which is much larger than the other three.

The genus _Stauroxiphos_ differs from its ancestral form, _Staurolonche_, in the greater development of one single spine, and exhibits therefore the same relation to it that _Stylostaurus_ bears to _Staurosphæra_.

1. _Stauroxiphos gladius_, n. sp. (Pl. 15, fig. 7).

Cortical shell thick walled, smooth, three times as broad as the medullary shell. Pores of the outer shell regular, circular, regularly six-lobed on the outer opening, four times as broad as the bars; about six on the quadrant. Pores of the inner shell only one-third as large, simple, circular. Three of the four radial spines of nearly equal size, pommel-shaped, with three prominent, dentated wings, somewhat shorter than the shell radius and about half as broad as long; the fourth spine much larger, sword-like, about three times as long as the shell radius.

_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.04; pores of the former 0.01, bars 0.0025; pores of the latter 0.003, bars 0.001; length of the major spine 0.18, of the three minor 0.04.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

Subfamily STAURACONTIDA,[91] Haeckel, 1881, Prodromus, p. 52.

_Definition._--#Staurosphærida# with three concentric spherical lattice-shells.

Genus 67. _Stauracontium_,[92] Haeckel, 1881, Prodromus, p. 452.

_Definition._--#Staurosphærida# with three concentric lattice-spheres and four crossed, equal, simple spines.

The genus _Stauracontium_ differs from its probable ancestral form, _Staurolonche_, in the duplication of the cortical shell.

Subgenus 1. _Stauracontarium_, Haeckel.

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

{164}1. _Stauracontium cruciferum_, n. sp.

Cortical shell thin walled, smooth, with regular, hexagonal pores, four times as broad as the bars; eight to ten on the quadrant. Radial proportion of the three spheres = 1 : 3 : 9. Connecting radial beams between them six (opposite in pairs in the three dimensive axes), but only four of them are prolonged outside into four stout three-sided prismatic spines, lying in one equatorial plane, as long as the shell diameter.

_Dimensions._--Diameter of the outer shell 0.22, middle 0.07, inner 0.025; cortical pores 0.012, bars 0.003; length of the spines 0.2.

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

2. _Stauracontium tetracanthum_, Haeckel.

_Haliomma tetracanthum_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 295, Taf. x. figs. 7, 8.

Cortical shell thin walled, smooth, with regular, circular pores, three times as broad as the bars; five to six on the quadrant. Radial proportion of the three spheres = 1 : 3 : 12. Radial spines three-sided pyramidal, about as long as the shell diameter.

_Dimensions._--Diameter of the outer shell 0.12, middle 0.03, inner 0.01; cortical pores 0.01, bars 0.003; length of the spines 0.1.

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

3. _Stauracontium tetracontium_, Haeckel.

_Actinomma tetracanthum_, Stöhr, 1880, Palæontogr. 26, p. 91, Taf. ii.
fig. 6.

Cortical shell thin walled, rough, with regular, circular pores, of the same breadth as the bars; six to seven on the quadrant. Radial proportion of the three spheres = 1 : 2.5 : 8. Radial spines three-sided pyramidal, nearly as long as the shell diameter.

_Dimensions._--Diameter of the outer shell 0.1, middle 0.03, inner 0.013; cortical pores and bars 0.006; length of the spines 0.08.

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

Subgenus 2. _Stauracontellium_, Haeckel.

_Definition._--Pores of the cortical shell regular, and of nearly equal size and similar form; surface covered with numerous small thorns or by-spines.

4. _Stauracontium daturæforme_, Haeckel.

_Actinomma daturæforme_, Stöhr, 1880, Palæontogr. 26, p. 93, Taf. ii.
fig. 13.

Cortical shell thick walled, covered with short thorns, and with regular, hexagonal pores, five times as broad as the bars; six to seven on the quadrant. Radial proportion of the three spheres = 1 : 3 : 3.5. Radial spines six-sided pyramidal, about half as long as the radius and one-fourth as broad.

{165}_Dimensions._--Diameter of the outer shell 0.15, middle 0.13, inner 0.04; cortical pores 0.017, bars 0.003; length of the spines 0.03.

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

5. _Stauracontium sparganium_, n. sp.

Cortical shell thick walled, covered with very numerous, short, conical spines, and with regular, circular pores, five times as broad as the bars; sixteen to eighteen on the quadrant. Radial proportion of the three spheres = 2 : 3 : 9. Radial main spines three-sided prismatic, as long as the radius or longer.

_Dimensions._--Diameter of the outer shell 0.275, middle 0.09, inner 0.06; cortical pores 0.01, bars 0.002; length of the spines 0.15.

_Habitat._--Fossil in Barbados.

Subgenus 3. _Stauracontidium_, Haeckel.

_Definition._--Pores irregular, of different size or form; surface smooth.

6. _Stauracontium antarcticum_, n. sp.

Cortical shell thin walled, smooth. Pores irregular, roundish, two to four times as broad as the bars. Radial proportion of the three spheres = 1 : 2 : 8. Radial spines conical, as long as the radius.

_Dimensions._--Diameter of the outer shell 0.2, middle 0.05, inner 0.025; cortical pores 0.006 to 0.012, bars 0.003; length of the spines 0.1.

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

Subgenus 4. _Stauracontonium_, Haeckel.

_Definition._--Pores irregular, of different size or form; surface covered with thorns or by-spines.

7. _Stauracontium setosum_, n. sp.

Cortical shell thin walled, covered with thin bristle-shaped by-spines, half as long as the radius. Pores irregular, polygonal, three to five times as broad as the bars. Proportion of the three spheres = 1 : 2 : 6. Radial main spines pyramidal, nearly as long as the shell diameter.

_Dimensions._--Diameter of the outer shell 0.15, middle 0.05, inner 0.025; cortical pores 0.01 to 0.015, bars 0.003; length of the spines 0.12.

_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.

8. _Stauracontium papillosum_, n. sp.

Cortical shell thick walled, covered with short conical papillæ or by-spines. Pores irregular, roundish, two to four times as broad as the bars. Proportion of the three spheres = 1 : 3 : 12. Radial main spines conical, as long as the radius.

{166}_Dimensions._--Diameter of the outer shell 0.24, middle 0.06, inner 0.02; cortical pores 0.007 to 0.015, bars 0.004; length of the spines 0.12.

_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.

Subfamily STAUROCROMYIDA,[93] Haeckel, 1881, Prodromus, pp. 449, 453.

_Definition._--#Staurosphærida# with four concentric spherical lattice-shells.

Genus 68. _Staurocromyum_,[94] Haeckel, 1881, Prodromus, p. 453.

_Definition._--#Staurosphærida# with four concentric lattice-spheres and four crossed, equal, simple spines.

The genus _Staurocromyum_ has arisen probably from _Stauracontium_ by duplication of the cortical shell, two concentric shells lying within, two others outside the central capsule.

1. _Staurocromyum quadruplex_, n. sp.

Radial proportion of the four spheres = 1 : 2 : 8 : 10. Both medullary shells with very small, regular, circular pores. Inner cortical shell with regular, circular, hexagonally-framed pores, twice as broad as the bars; from each hexagon-corner arises a small by-spine, and these, connected by tangential branches at equal distances from the centre, form the delicate outer cortical shell, with spiny surface. Four main spines three-sided pyramidal, as long as the shell radius.

_Dimensions._--Diameter of the four shells--(A) 0.25, (B) 0.2, (C) 0.05, (D) 0.025; length of the spines 0.12.

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

2. _Staurocromyum quadrispinum_, n. sp.

Radial proportion of the four spheres = 1 : 3 : 9 : 12. Both medullary shells with small, regular, circular pores. Both cortical shells with irregular, roundish pores. Surface covered with short, conical by-spines. Four main spines cylindro-conical, somewhat longer than the shell diameter.

_Dimensions._--Diameter of the four shells--(A) 0.24, (B) 0.18, (C) 0.06, (D) 0.02.

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

Genus 69. _Cromyostaurus_,[95] Haeckel, 1881, Prodromus, p. 453.

_Definition._--#Staurosphærida# with four concentric lattice-spheres and four crossed, equal, branched spines.

{167}The genus _Cromyostaurus_ differs from the preceding _Staurocromyum_, its ancestral form, in the ramification of the four crossed spines.

1. _Cromyostaurus verticillatus_, n. sp.

Radial proportion of the four spheres = 1 : 3 : 11 : 13. Both medullary shells with small, regular, circular pores; inner cortical shell with regular, hexagonal pores; from the hexagon-corners arise small, radial by-spines, which at equal distances from the centre send out forked tangential branches, three from each spine, and by communication of these form the outer, delicate, cortical shell. Four main spines nearly as long as the shell diameter, three-sided prismatic, with four to six verticils of ramified lateral branches, each verticil composed of three forked branches, which ramify again.

_Dimensions._--Diameter of the four shells--(A) 0.26, (B) 0.22, (C) 0.06, (D) 0.02; length of the spines 0.24.

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

Subfamily STAUROCARYIDA,[96] Haeckel, 1881, Prodromus, pp. 449, 454.

_Definition._--#Staurosphærida# with five or more concentric spherical lattice-shells.

Genus 70. _Staurocaryum_,[97] Haeckel, 1881, Prodromus, p. 454.

_Definition._--#Staurosphærida# with five or more concentric lattice-spheres and four crossed, equal spines.

The genus _Staurocaryum_ has arisen from the preceding _Staurocromyum_ by the further multiplication of the concentric spheres; in the only observed form there are six, at nearly equal distances apart.

1. _Staurocaryum arborescens_, n. sp. (Pl. 15, fig. 8).

Shell composed of six concentric latticed spheres, at nearly equal distances apart, and with somewhat regular, circular pores, the size of which gradually increases from the first to the sixth shell. The surface of the outermost shell is densely covered with numerous arborescent by-spines, which bifurcate from three to four times, and are three-sided pyramidal at the base, and twice as long as the distance between each two shells. The six shells are connected only by four crossed, conical, radial beams, which increase in diameter from the centre, and are prolonged outside into very stout cylindrical, radial spines, irregularly covered with small thorns and forked ramules, and nearly as long as the shell diameter. Only a single specimen was observed.

{168}_Dimensions._--Diameter of the whole shell 0.22; distance between each two shells 0.02; length of the by-spines 0.05, of the main spines 0.2.

_Habitat._--Indian Ocean, Cocos Islands, surface, Rabbe.

Subfamily STAURODORIDA,[98] Haeckel, 1881, Prodromus, pp. 449, 455.

_Definition._--#Staurosphærida# with spongy, spherical shell (with or without enclosed concentric lattice-shells).

Genus 71. _Staurodoras_,[99] Haeckel, 1881, Prodromus, p. 455.

_Definition._--#Staurosphærida# with solid, spongy, spherical shell and four crossed simple spines.

The genus _Staurodoras_ may be developed from _Styptosphæra_ by the production of four crossed spines on the simple, spongy, spherical shell, which is composed of looser or denser irregular wicker-work, without enclosed medullary shell.

1. _Staurodoras spongosphæra_, n. sp.

Four crossed spines, two to three times as long as the diameter of the spongy sphere, three-sided prismatic, with three dentated and spirally contorted edges. (Form of _Spongosphæra streptacantha_, but without medullary shell and with four equal spines, crossed regularly at right angles.)

_Dimensions._--Diameter of the sphere 0.25; length of the spines 0.4 to 0.7.

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

2. _Staurodoras mojsisovicsi_, Dunikowski.

_Staurodoras mojsisovicsi_, Dunikowski, 1882, Denkschr. d. k. Akad. d.
Wiss. Wien, Bd. xlv. p. 28, Taf. v. fig. 56.

Four crossed spines, one and a half times as long as the diameter of the spongy sphere, three-sided pyramidal, with three smooth edges. (What Dunikowski describes as "inner canals" of the spines are their edges.)

_Dimensions._--Diameter of the sphere 0.14; length of the spines 0.18 to 0.2. basal breadth 0.04.

_Habitat._--Fossil in the Alpine Lias (Schafberg near Salzburg).

3. _Staurodoras liassica_, Dunikowski.

_Staurodoras liassica_, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss.
Wien, Bd. xlv. p. 28, Taf. v. fig. 57.

Four crossed spines, shorter than the diameter of the spongy sphere, conical or pyramidal (?).

_Dimensions._--Diameter of the sphere 0.19; length of the spine 0.13, basal breadth 0.045.

_Habitat._--Fossil in the Alpine Lias (Schafberg near Salzburg).

{169}4. _Staurodoras wandae_, Dunikowski.

_Staurodoras wandae_, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss.
Wien, Bd. xlv. p. 28, Taf. v. fig. 58.

Four crossed spines shorter than the radius of the spongy sphere, conical. (May be the young form of the preceding species.)

_Dimensions._--Diameter of the sphere 0.14; length of the spines 0.06, basal breadth 0.05.

_Habitat._--Fossil in the Alpine Lias (Schafberg near Salzburg).

Family IX. #CUBOSPHÆRIDA#, Haeckel (Pls. 21-25).

_Cubosphærida_, Haeckel, 1881, Prodromus, p. 449.

_Definition._--#Sphæroidea# with six radial spines on the surface of the spherical shell, opposite in pairs in the three dimensive axes, perpendicular one to another; living solitary (not associated in colonies).

The family #Cubosphærida# is distinguished from the other #Sphæroidea# by the possession of six radial spines, which are opposite in pairs in three different axes, one perpendicular to the other two. These three axes are the typical "dimensive axes," which are more or less differentiated in the #Larcoidea#. But in these latter the shell itself and the enclosed central capsule become affected by the unequal growth in the three axes, whilst in the former the capsule constantly, and commonly also the shell, remains spherical. Sometimes the shell assumes the form of a regular octahedron, from the six corners of which arise the six radial spines, indicating its three axes.

The most simple Cubosphærida are the Hexastylida, with one single, spherical lattice-shell. To this ancestral group all other subfamilies can be opposed as "Cubosphærida concentrica," as their carapace is composed of two or more concentric lattice-shells--two in the Hexalonchida, three in the Hexacontida, four in the Hexacromyida, five or more in the Hexacaryida. In all these four subfamilies the concentric shells are simple (not spongy), fenestrated spheres. In a sixth subfamily, in the Hexadorida, the shell is wholly or partially composed of irregular, spongy wicker-work or loose reticulations, with or without a medullary shell in the centre.

The _Six Radial Spines_ of the Cubosphærida are normally opposite in pairs in the three dimensive axes, each of which is perpendicular to the other two. But in many species besides this normal form occur individual abnormalities, in which the six spines are not quite accurately opposed, but more or less divergent; and often also the three dimensive planes (determined each by two axes) are not quite regular, but more or less uneven. More rarely the six spines appear disposed in quite an irregular manner.

In the greater part of the Cubosphærida all six spines are quite equal, of the same size and form. But in some genera a more or less considerable differentiation takes place, so {170}that two pairs or all three pairs of spines become different; very rarely, also both spines of one pair become unequal (probably only an individual abnormality). Those variations correspond to the differences between the crystalline systems. The common Cubosphærida, with three equal spine-pairs, correspond to the regular or cubic system, with three equal axes. The rarer forms (_Hexastylarium_, _Hexaloncharium_, _Hexacontarium_) exhibit two equal pairs and one different pair; they correspond to the quadratic system, with three perpendicular axes, two of which are equal, the third unequal. Still more rare are those forms (_Hexastylidium_, _Hexalonchidium_), in which all three pairs of spines are different, corresponding to the three unequal axes of the rhombic crystalline system.

_Synopsis of the Genera of Cubosphærida._

{All six radial spines simple,
I. Subfamily { of equal size, 72. _Hexastylus_.
Hexastylida. {
(Shell one {Six spines of {Two pairs equal,
simple { different sizes,{ one pair
latticed { all six simple. { different, 73. _Hexastylarium_.
sphere.) { {
{ {All three pairs
{ { different, 74. _Hexastylidium_.

{All six radial {Spines simple, 75. _Hexalonche_.
{ spines of {
II. Subfamily { equal size. {Spines branched, 76. _Hexancistra_.
Hexalonchida. {
(Shell composed {Six spines {Two pairs equal,
of two { simple, in { one pair
concentric { pairs of { different, 77. _Hexaloncharium_.
latticed { different sizes.
spheres.) { {All three pairs
{ { different, 78. _Hexalonchidium_.

{All six radial {Spines simple, 79. _Hexacontium_.
III. Subfamily { spines of {
Hexacontida. { equal size. {Spines branched, 80. _Hexadendron_.
(Shell composed {
of three {Six spines Two pairs equal,
spheres.) { simple, of one pair
{ different sizes. different, 81. _Hexacontarium_.

IV. Subfamily }All six radial Spines simple,
Hexacromyida. } spines of not branched, 82. _Hexacromyum_.
(Four concentric} equal size.
spheres.) }

V. Subfamily }All six radial {Spines simple, 83. _Cubosphæra_.
Hexacaryida. } spines of {
(Five or more } equal size. {Spines branched, 84. _Hexacaryum_.
spheres.) }

{Without latticed
{ medullary
VI. Subfamily }All six radial { shell, 85. _Cubaxonium_.
Hexadorida. } spines of {
(Shell a spongy } equal size, {With one single
sphere, with } simple (not { medullary
or without an } branched). { shell, 86. _Hexadoras_.
enclosed } {
central } {With two
medullary } { medullary
shell.) } { shells, 87. _Hexadoridium_.

{171}Subfamily HEXASTYLIDA,[100] Haeckel, 1881, Prodromus, pp. 449, 450.

_Definition._--#Cubosphærida# with one single spherical lattice-shell.

Genus 72. _Hexastylus_,[101] Haeckel, 1881, Prodromus, p. 450.

_Definition._--#Cubosphærida# with one simple lattice-sphere and six simple spines of equal size.

The genus _Hexalonche_ is the most simple form of all Cubosphærida, and may be regarded as the common ancestral form of this family. It can be derived phylogenetically from _Cenosphæra_, by development of six radial spines on the surface of the simple spherical lattice-shell. These six simple spines are of equal size and opposite in pairs in the three dimensive axes, corresponding to the three equal axes of a cubic crystal.

Subgenus 1. _Hexastylanthus_, Haeckel.

_Definition._--Pores regular or subregular, of nearly equal size and form; surface of the cortical shell smooth, without radial by-spines (other than the six main spines).

1. _Hexastylus phænaxonius_, n. sp. (Pl. 21, fig. 3).

Shell thin walled, with smooth surface. Pores subregular, hexagonal, five to six times as broad as the bars; nine to ten on the radius. Six spines triangular pyramidal, as long as the radius of the shell, as broad at the base as one pore.

_Dimensions._--Diameter of the shell 0.13, pores 0.008 to 0.01, bars 0.0015; length of the spines 0.07, basal breadth 0.008 to 0.012.

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

2. _Hexastylus sapientum_, n. sp.

Shell thin walled, with smooth surface. Pores regular, hexagonal, eight to ten times as broad as the bars; six to seven on the radius. Six spines bristle-shaped, longer than the diameter of the shell. (Lattice-work and spines similar to those of _Heliosphæra actinota_, Monogr. d. Radiol., Taf. ix. fig. 3.)

_Dimensions._--Diameter of the shell 0.15, pores 0.016, bars 0.002; length of the spines 0.2, breadth 0.002.

_Habitat._--North Atlantic, Station 354, surface.

{172}3. _Hexastylus thaletis_, n. sp. (Pl. 21, fig. 4).

Shell thin walled, with smooth surface. Pores subregular, circular, hexagonally framed, somewhat funnel-shaped, of the same breadth as the bars; eight to nine on the radius. Six spines triangular pyramidal, with prominent edges, as long as the radius, three to four times as broad at the base as one pore.

_Dimensions._--Diameter of the shell 0.1, pores and bars 0.005; length of the spines 0.05, basal breadth 0.02.

_Habitat._--Tropical Pacific, Station 225, depth 4575 fathoms.

4. _Hexastylus favosus_, n. sp.

Shell thick walled, with smooth surface. Pores regular, circular, hexagonally framed, deep funnel-shaped, of the same breadth as the bars; six to seven on the radius. Six spines triangular pyramidal, as long as the diameter, twice as broad at the base as one pore.

_Dimensions._--Diameter of the shell 0.12, pores and bars 0.01; length of the spines 0.12, basal breadth 0.02.

_Habitat._--South Atlantic, Station 320, surface.

5. _Hexastylus longissimus_, n. sp.

Shell thick walled, with smooth surface. Pores regular, circular, hexagonally framed, of the same breadth as the bars; five to six on the radius. Six spines triangular prismatic, extremely elongated, ten to twenty times as long as the diameter of the shell, twice as broad as one pore.

_Dimensions._--Diameter of the shell 0.08, pores and bars 0.008; length of the spines 1.0 to 1.5, breadth 0.015.

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

6. _Hexastylus minimus_, n. sp. (Pl. 21, fig. 5).

Shell thin walled, with smooth surface. Pores subregular, circular, twice as broad as the bars; five to six on the radius. Six spines triangular pyramidal, scarcely as long as the radius, at the base half as broad as long.

_Dimensions._--Diameter of the shell 0.05, pores 0.004, bars 0.002; length of the spines 0.02, basal breadth 0.01.

_Habitat._--Tropical Pacific, Station 225, depth 4575 fathoms.

7. _Hexastylus biantis_, n. sp.

? _Haliphormis hexacantha_, Ehrenberg, 1872, L. N. 24, Taf. x. fig. 6.

Shell thin walled, smooth. Pores regular, circular, four times as broad as the bars; eight to nine on the radius. Six spines conical, as long as the radius, at the base as broad as one pore.

{173}_Dimensions._--Diameter of the shell 0.12, pores 0.012, bars 0.003; length of the spines 0.06, basal breadth 0.012.

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

8. _Hexastylus pittaci_, n. sp.

Shell thin walled, smooth. Pores regular, circular, ten to twelve times as broad as the bars; six to seven on the radius. Six spines triangular pyramidal, as long as the radius, as broad as one pore.

_Dimensions._--Diameter of the shell 0.12, pores 0.02, bars 0.002; length of the spines 0.06, basal breadth 0.02.

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

9. _Hexastylus maximus_, n. sp.

Shell thick walled, smooth. Pores regular, circular, twice as broad as the bars; twelve to sixteen on the radius. Six spines six-sided pyramidal, half as long as the radius, three times as broad as one pore.

_Dimensions._--Diameter of the shell 0.3, pores 0.01, bars 0.005; length of the spines 0.08, basal breadth 0.03.

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

10. _Hexastylus periandri_, n. sp.

Shell thick walled, smooth. Pores regular, circular, double-edged, four times as broad as the bars; six to seven on the radius. Six spines conical, as long as the radius, twice as broad as one pore.

_Dimensions._--Diameter of the shell 0.2, pores 0.012, bars 0.003; length of the spines 0.1, basal breadth 0.025.

_Habitat._--Tropical Atlantic, Station 335, depth 1425 fathoms.

Subgenus 2. _Hexastylettus_, Haeckel.

_Definition._--Pores regular or subregular, of nearly equal size and form; surface of the spherical shell spiny, covered with numerous conical or bristle-shaped radial by-spines.

11. _Hexastylus solonis_, n. sp. (Pl. 21, fig. 11).