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).
Shell thick walled, covered with numerous bristle-shaped radial spines
(one-third to one-half as long as the six main spines, arising from the
lattice-knots). Pores regular, circular, enclosed by prominent, hexagonal
frames, four to six times as broad as the bars; seven to eight on the
radius. {174}Six main spines triangular pyramidal, with spirally contorted
prominent edges, as long as the radius, as broad at the base as one pore.
_Dimensions._--Diameter of the shell 0.13, pores 0.01, bars 0.002; length
of the spines 0.06 to 0.8, basal breadth 0.01.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
12. _Hexastylus cochleatus_, n. sp. (Pl. 21, fig. 1).
Shell thick walled, covered with numerous short, conical spines (about as
large as one pore). Pores regular, circular, three times as broad as the
bars; eight to nine on the radius. Six main spines triangular pyramidal,
with prominent, spirally-twisted edges, as long as the diameter of the
shell, and twice as broad at the base as one pore.
_Dimensions._--Diameter of the shell 0.17, pores 0.015, bars 0.005; length
of the spines 0.16, breadth 0.03.
_Habitat._--Mediterranean, Corfu, Haeckel, surface.
13. _Hexastylus setosus_, Haeckel.
_Acanthosphæra setosa_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 285, Taf. ix. fig. 11.
Shell thin walled, covered with numerous short, bristle-shaped spines (not
larger than one pore). Pores regular, circular, four times as broad as the
bars; thirteen to sixteen on the radius. Six main spines three-sided
pyramidal, scarcely one-third as long as the radius. (In the figure of
Ehrenberg, _loc. cit._, only four spines are in regular, crossed
disposition, two others opposite in oblique direction; this is either an
individual abnormality, or an error of drawing; the same species occurs
with six spines exactly regularly disposed in the three dimensive axes.)
_Dimensions._--Diameter of the shell 0.15; pores 0.008, bars 0.002; length
of the spines 0.02 to 0.03, basal breadth 0.005.
_Habitat._--Indian Ocean, Zanzibar, Pullen; Madagascar, Rabbe.
14. _Hexastylus chilonis_, n. sp.
Shell thin walled, covered with numerous bristle-shaped spines (as long as
the radius). Pores regular, circular, twice as broad as the bars; eight to
nine on the radius. Six main spines triangular pyramidal, with straight
edges, as long as the diameter of the shell, as broad as two pores.
_Dimensions._--Diameter of the shell 0.2, pores 0.02, bars 0.01; length of
the spines 0.2, basal breadth 0.05.
_Habitat._--South Atlantic, Station 325, surface.
15. _Hexastylus cleobuli_, n. sp.
Shell thick walled, covered with numerous short, conical spines (twice as
large as one pore). Pores regular, circular, of the same breadth as the
bars; twelve to thirteen on the radius. Six main spines conical, as long as
the radius, three times as broad as one pore.
{175}_Dimensions._--Diameter of the shell 0.24, pores and bars 0.005;
length of the spines 0.12, basal breadth 0.016.
_Habitat._--South Pacific, Station 300, depth 1375 fathoms.
Subgenus 3. _Hexastylissus_, Haeckel.
_Definition._--Pores irregular, of unequal size or form; surface of the
spherical shell smooth, without radial by-spines (other than the six main
spines).
16. _Hexastylus triaxonius_, n. sp. (Pl. 21, fig. 2).
Shell thin walled, with smooth surface. Pores irregular, polygonal, three
to six times as broad as the bars; four to six on the radius. Six spines
triangular pyramidal, as long as the diameter of the shell, as broad at the
base as one pore.
_Dimensions._--Diameter of the shell 0.05, pores 0.004 to 0.008, bars
0.0015; length of the spines 0.04, basal breadth 0.006.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
17. _Hexastylus dimensivus_, n. sp. (Pl. 21, fig. 6).
Shell thin walled, with smooth surface. Pores irregular, polygonal, four to
eight times as broad as the bars; eleven to thirteen on the radius. Six
spines hexagonal pyramidal, as long as the radius, about three times as
broad at the base as one pore.
_Dimensions._--Diameter of the shell 0.13, pores 0.006 to 0.009, bars
0.0012; length of the spines 0.06, basal breadth 0.025.
_Habitat._--North Pacific, Station 256, depth 2950 fathoms.
18. _Hexastylus brevispinus_, n. sp.
Shell thin walled, with smooth surface. Pores irregular, roundish, two to
four times as broad as the bars; six to eight on the radius. Six spines
triangular pyramidal, half as long as the radius, twice as broad as one
pore.
_Dimensions._--Diameter of the shell 0.2, pores 0.008 to 0.016, bars 0.004;
length of the spines 0.05, basal breadth 0.025.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
19. _Hexastylus longispinus_, n. sp.
Shell thick walled, smooth. Pores irregular, roundish, two to three times
as broad as the bars; three to four on the radius. Six spines triangular
prismatical, two to three times as long as the diameter of the shell.
{176}_Dimensions._--Diameter of the shell 0.08, pores 0.008 to 0.012, bars
0.004; length of the spines 0.2, breadth 0.01.
_Habitat._--North Atlantic, Station 353, surface.
20. _Hexastylus marginatus_, n. sp. (Pl. 21, fig. 10).
Shell thick walled, rough. Pores irregular, roundish, somewhat
funnel-shaped double-edged, two to three times as broad as the bars; twelve
to fourteen on the radius. Six spines three-sided pyramidal, somewhat
longer than the radius, three times as broad as one pore.
_Dimensions._--Diameter of the shell 0.15, pores 0.007 to 0.01, bars 0.004;
length of the spines 0.1, basal breadth 0.025.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
21. _Hexastylus conifer_, n. sp.
Shell thick walled, rough. Pores irregular, roundish, scarcely broader than
the bars; fifteen to sixteen on the radius. Six spines conical, as long as
the radius, five to seven times as broad as one pore.
_Dimensions._--Diameter of the shell 0.18, pores and bars 0.004 to 0.006;
length of the spines 0.1, basal breadth 0.03.
_Habitat._--Indian Ocean, Sunda Strait, Rabbe, surface.
Subgenus 4. _Hexastylurus_, Haeckel.
_Definition._--Pores irregular, of unequal size or form; surface of the
spherical shell spiny, covered with numerous conical or bristle-shaped
by-spines.
22. _Hexastylus dictyotus_, n. sp. (Pl. 21, figs. 8, 9).
Shell thin walled, spiny; short spines conical, smaller than the
pore-breadth. Pores irregular, polygonal, five to seven times as broad as
the bars; four to six on the radius. Six spines triangular pyramidal,
longer than the radius, about as broad as one smaller pore.
_Dimensions._--Diameter of the shell 0.09, pores 0.01 to 0.015, bars 0.002;
length of the spines 0.06, basal breadth 0.01.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
23. _Hexastylus hirsutus_, n. sp.
Shell thin walled, densely covered with bristle-shaped, radial spines, half
as long as the six main spines. Pores irregular, polygonal, three to four
times as broad as the bars; eight to ten on the radius. Six spines
triangular pyramidal, as long as the radius, twice as broad as one pore.
{177}_Dimensions._--Diameter of the shell 0.14, pores 0.005 to 0.008, bars
0.002; length of the spines 0.06, basal breadth 0.01.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
24. _Hexastylus contortus_, n. sp. (Pl. 21, fig. 12).
Shell thick walled, covered with bristle-shaped, radial spines, half as
long as the radius. Pores irregular, roundish, two to three times as broad
as the bars; seven to eight on the radius. Six spines triangular prismatic,
in the distal half spirally twisted like a cork-screw (fig. 12); longer
than the diameter of the shell, about as broad as one pore.
_Dimensions._--Diameter of the shell 0.12, pores 0.006 to 0.008, bars
0.003; length of the spines 0.15, breadth 0.015.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
25. _Hexastylus spiralis_, n. sp. (Pl. 21, fig. 7).
Shell thick walled, covered with short conical spines. Pores irregular,
roundish, two to three times as broad as the bars; five to six on the
radius. Six spines triangular prismatic, with three thin, spirally
contorted edges, two to three times as long as the diameter of the shell,
about as broad as one large pore.
_Dimensions._--Diameter of the shell 0.16, pores 0.01 to 0.02, bars 0.006;
length of the spines 0.3 to 0.5, basal breadth 0.02.
_Habitat._--Tropical Western Pacific, Station 225, depth 4475 fathoms.
Genus 73. _Hexastylarium_,[102] n. gen.
_Definition._--#Cubosphærida# with one simple lattice-sphere and six simple
spines of different sizes; one opposite pair larger than the other two.
The genus _Hexastylarium_ differs from its probable ancestral form,
_Hexastylus_, by the unequal growth of the six simple spines; two opposite
spines of one pair being more strongly developed than the four others,
which are equal. They correspond therefore to the three axes of a quadratic
crystal.
1. _Hexastylarium heteraxonium_, n. sp.
Cortical shell thin walled, smooth, with regular, hexagonal pores, three
times as broad as the bars; eight to ten on the radius. Six spines
three-sided pyramidal, at the base as broad as one pore. Two opposite major
spines longer than the shell diameter; four others scarcely as long as
{178}the radius. (Similar to _Hexastylus phænaxonius_, Pl. 21, fig. 3, but
differing in the unequal length of the spines.)
_Dimensions._--Diameter of the shell 0.15, pores 0.12, bars 0.004; length
of the two major spines 0.2, of the four minor 0.07.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
2. _Hexastylarium quadratum_, n. sp.
Shell very delicate, with smooth surface, and irregular, polygonal pores,
separated by very thin bars. The form of the shell is not, as commonly, a
sphere, but a geometrical square octahedron, one axis (with two opposite
major spines) being nearly twice as long as the other two dimensive axes;
four spines, opposite by pairs in the latter, are only half as long. The
eight sides of the octahedral shell are even, equilateral-triangular.
Spines angular, thin.
_Dimensions._--Diameter of the shell in the major axis 0.18, in the minor
0.1; length of the major spines 0.24, minor 0.12.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
3. _Hexastylarium elongatum_, n. sp.
Shell thick walled, with spiny surface, and with irregular, roundish pores,
two to four times as broad as the bars; eight to ten on the radius. Two
opposite major spines, three to four times as long as the shell diameter,
whilst the four other spines are very short, scarcely as long as the
radius. All six spines at the base three-sided pyramidal, the two longer
being cylindrical.
_Dimensions._--Diameter of the shell 0.1; length of the major spines 0.3 to
0.4, of the minor 0.04, basal breadth 0.02.
_Habitat._--North Pacific, Station 244, surface.
Genus 74. _Hexastylidium_,[103] Haeckel, 1881, Prodromus, p. 450.
_Definition._--#Cubosphærida# with one simple lattice-sphere and six simple
spines in pairs different; the two opposite spines of each pair equal, the
three pairs unequal.
The genus _Hexastylidium_ differs from its probable ancestral form,
_Hexastylus_, by the unequal growth of the six simple spines; the two
spines of each pair reaching the same dimensions, whilst the three pairs
are different. They correspond therefore to the three axes of a rhombic
crystal.
1. _Hexastylidium rhomboides_, n. sp.
Shell thin walled, smooth, with irregular, polygonal pores and very thin
bars. Its form is not, as commonly, a sphere, but a rhombic octahedron. The
radial proportion of the three unequal {179}dimensive axes = 1 : 2 : 4. The
radial proportion of the three pairs of spines = 1 : 3 : 8. Spines thin
cylindrical, at the base angular.
_Dimensions._--Diameter of the major shell axis 0.2, middle 0.1, minor
0.05; length of the major spines 0.3, middle 0.12, minor 0.04.
_Habitat._--Indian Ocean, Madagascar, Rabbe, surface.
2. _Hexastylidium spirale_, n. sp.
Shell thick walled, spherical, thorny, with irregular, roundish pores,
three to five times as broad as the bars; six spines very stout, prismatic
(as broad as one large pore), with three ring-like, spirally convoluted
edges. Two opposite major spines of extraordinary length, ten to twelve
times as long as the shell diameter, the two middle opposite spines being
about as long as the latter, the two minor scarcely one-third as long.
(Similar to _Hexastylus spiralis_, Pl. 21, fig. 7, but distinguished by the
very unequal length of the spines.)
_Dimensions._--Diameter of the shell 0.12; length of the major spines 1 to
1.5 mm., middle 0.15, minor 0.04.
_Habitat._--Central Pacific, Station 266, surface.
Subfamily HEXALONCHIDA,[104] Haeckel, 1881, Prodromus, pp. 449, 451.
_Definition._--#Cubosphærida# with two concentric spherical lattice-shells.
Genus 75. _Hexalonche_,[105] Haeckel, 1881, Prodromus, p. 451.
_Definition._--#Cubosphærida# with two concentric lattice-spheres and six
simple spines of equal size.
The genus _Hexalonche_ is the most simple form, and probably the common
ancestral form, of all Hexalonchida, or those Cubosphærida which possess
two concentric latticed spheres, connected by six radial beams. Commonly
one shell is intracapsular (medullary shell) and the other extracapsular
(cortical shell); but sometimes also both shells are extracapsular, and
these forms may perhaps be better separated as a peculiar genus
_Hexadilemma_. In _Hexalonche_ all six simple spines are of equal size, and
opposite by pairs in three equal dimensive axes, corresponding to the three
equal axes of a tesseral crystal. It can be derived from _Hexastylus_ by
duplication of the lattice-shell.
Subgenus 1. _Hexalonchara_, Haeckel.
_Definition._--Pores of the cortical shell regular or subregular, of nearly
equal size and similar form; surface smooth, without radial by-spines
(other than the six main spines).
{180}1. _Hexalonche phænaxonia_, n. sp.
Cortical shell thin walled, smooth; its pores regular, hexagonal, six to
eight times as broad as the bars; eight to ten to twelve on the radius.
Medullary shell one-third as broad, with regular, hexagonal pores of half
size. Six spines triangular pyramidal, as long as the radius of the shell,
at the base as broad as one pore. (Differs from _Hexastylus phænaxonius_,
Pl. 21, fig. 3, only in the medullary shell and the six inner radial beams,
connecting it with the cortical shell.)
_Dimensions._--Diameter of the outer shell 0.15, pores 0.01 to 0.015, bars
0.015 to 0.02; inner shell 0.05; length of the spines 0.08, basal breadth
0.01.
_Habitat._--Central Pacific, Stations 266 to 271, depth 2425 to 2925
fathoms.
2. _Hexalonche rosetta_, n. sp. (Pl. 25, figs. 3, 3_a_, 3_b_).
Cortical shell thick walled, smooth, two and a half time as broad as the
medullary shell. Pores of the latter (fig. 3_a_) regular circular; eight to
ten on the half meridian, about as broad as the bars between them. Pores of
the outer shell regular, hexagonal, remarkable for a very peculiar form and
arrangement. In the transverse section of the shell (fig. 3_b_) they appear
as narrow, hexagonal prismatic canals, twice as high as broad, and four to
five times as broad as the thin elevated bars between them. Every seven
meshes form together a larger, regular hexagon (six pores surrounding one
central pore). The periphery of these larger, rosette-like hexagons
projects more strongly from the surface than the walls between the smaller
hexagons. On the half meridian of the shell may be counted six to seven
larger and eighteen to twenty smaller hexagons. The six radial beams
between the two shells are thin, three-sided prismatic, not broader than
the bars of the network, the prominent prolongations of which form six very
strong spines of peculiar club-like shape (fig. 3), as long as the radius
of the outer shell. The three wings of the club are lower in the inner,
higher in the outer half; the broadest part of the spine (at the base and
in the outer third) is as broad as a hexagonal rosette (equal to three
meshes of the outer shell); its outer apex is pyramidal.
_Dimensions._--Diameter of the outer shell 0.13, pores 0.008 to 0.01, bars
0.02; inner shell 0.05; length of the spines 0.07, distal breadth 0.03.
_Habitat._--Tropical West Pacific, Station 225, depth 4475 fathoms.
3. _Hexalonche favosa_, n. sp.
Cortical shell thick walled, smooth, four times as broad as the medullary
shell. Pores of the former regular circular, hexagonally framed, deep
funnel-shaped, of the same breadth as the bars; six to eight on the radius.
Six spines triangular-pyramidal, as long as the radius, at the base twice
as broad as one pore. (Differs from the similar _Hexastylus favosus_ mainly
in the possession of a medullary shell.)
_Dimensions._--Diameter of the outer shell 0.16, pores and bars 0.012;
inner shell 0.04; length of the spines 0.08, basal breadth 0.025.
_Habitat._--Equatorial Atlantic, Station 348, depth 2450 fathoms; also
fossil in Barbados.
{181}4. _Hexalonche octahedra_, n. sp. (Pl. 22, figs. 8, 8_a_).
Cortical shell a regular octahedron, thin walled, with twelve more or less
rounded edges (between the bases of the spines), and with smooth surface,
three times as broad as the spherical medullary shell. Pores of the former
regular circular (three times as large as those of the latter), four times
as broad as the bars; five to seven on the radius. Six spines three-sided
prismatic, with thickened base and cuspidated end, somewhat longer than the
radius, and once to twice as broad as one pore.
_Dimensions._--Diameter of the outer shell 0.11, pores 0.01, bars 0.0025;
inner shell 0.04; length of the spines 0.08, bars 0.01.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
5. _Hexalonche conicornis_, n. sp. (Pl. 22, fig. 2).
Cortical shell thick walled, smooth, three times as broad as the medullary
shell. Pores of both spheres regular circular, three to four times as broad
as the bars; those of the thick walled outer shell six to seven on the
radius, twice as large as those of the thin walled inner shell; six radial
beams between the two spheres, very thin, cylindrical; six spines short,
conical, scarcely as long as the radius of the outer shell, at the base
twice as broad as one pore.
_Dimensions._--Diameter of the outer shell 0.12 to 0.14, pores 0.01, bars
0.003; inner shell 0.04 to 0.05; length of the spines 0.04 to 0.06, basal
breadth 0.02.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
6. _Hexalonche curvicornis_, n. sp. (Pl. 25, fig. 4).
Cortical shell thick walled, smooth, not much larger than the medullary
shell (= 4 : 3). Pores of both spheres regular circular, nearly of the same
size, three times as broad as the bars between them; seven to nine on the
radius. Six spines three-sided prismatic, inside and outside of the
exterior shell of equal thickness, twice as broad as one pore, longer than
the diameter of the outer shell, and in a singular manner curved like an ox
horn; the three edges of each horn somewhat spirally twisted.
_Dimensions._--Diameter of the outer shell 0.16, pores 0.01, bars 0.003;
inner shell 0.12; length of the spines 0.2, breadth 0.02.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
7. _Hexalonche brevicornis_, n. sp.
Cortical shell thin walled, smooth, three times as broad as the medullary
shell. Pores of the former regular circular, double-edged, six to eight
times as broad as the thin bars, five to six on the radius. Six spines
triangular pyramidal, as broad as one pore and only twice as long.
_Dimensions._--Diameter of the outer shell 0.14, pores 0.02, bars 0.003;
inner shell 0.045; length of the spines 0.05, basal breadth 0.02.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
{182}8. _Hexalonche grandis_, n. sp.
Cortical shell thick walled, smooth, four times as broad as the medullary
shell. Pores of the outer shell regular circular, four times as broad as
the bars; thirteen to fifteen on the radius. Six spines conical, scarcely
half as long as the radius, at the base as broad as one pore.
_Dimensions._--Diameter of the outer shell 0.2 to 0.32, pores 0.01 to 0.02,
bars 0.003 to 0.005; inner shell 0.06 to 0.08; length of the spines 0.06,
breadth 0.02.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
Subgenus 2. _Hexalonchetta_, Haeckel.
_Definition._--Pores of the cortical shell regular or subregular, of nearly
equal size and similar form; surface covered with numerous conical or
bristle-shaped radial by-spines.
9. _Hexalonche amphisiphon_, n. sp. (Pl. 25, figs. 2, 2_a_, 2_b_).
Cortical shell thin walled, armed with very numerous bristle-shaped, radial
by-spines, a quarter to a half as long as the six main spines. Pores
regular hexagonal, twelve to fourteen on the radius, with very thin bars,
prolonged on the outer as well as the inner surface into a short truncated
conical tube (Pl. 25, fig. 2_b_). Medullary shell octahedral, with
irregular polygonal meshes and very thin bars between them (fig. 2_a_),
connected with the outer (six to eight times larger) shell by six very thin
radial beams. These are prolonged outside into six strong pyramidal spines,
nearly as long as the diameter of the outer shell, with sharp straight
edges, at the base twice as broad as one pore.
_Dimensions._--Diameter of the outer shell 0.15, pores 0.01, bars 0.001;
inner shell 0.02; length of the spines 0.12, basal breadth 0.02.
_Habitat._--Central Pacific, Station 271, surface.
10. _Hexalonche anaximandri_, n. sp. (Pl. 22, fig. 5).
Cortical shell thin walled, covered with short conical spines (smaller than
the pores), three times as broad as the medullary shell. Pores of the outer
shell subregular hexagonal, four times as broad as the bars; five to seven
on the radius. Inner shell with regular hexagonal pores of half the size,
connected with the outer by six strong, three-sided prismatic beams, which
are prolonged outside into six very stout pyramidal spines, with three
prominent edges, longer than the radius and twice as broad as one pore.
_Dimensions._--Diameter of the outer shell 0.12, pores 0.01, bars 0.0025;
inner shell 0.04; length of the spines 0.07, basal breadth 0.02.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
{183}11. _Hexalonche octocolpa_, n. sp. (Pl. 22, figs. 6, 6_a_).
Cortical shell thin walled, nearly octahedral, with eight hemispherical or
bosom-shaped vaultings, corresponding to the eight faces of a regular
octahedron, the three axes of which are indicated by the six spines.
Surface covered with short bristle-shaped spines. Pores regular hexagonal,
ten to fifteen times as broad as the thin bars; seven to nine on the
radius. Medullary shell (fig. 6_a_) spherical, with regular circular pores,
one-third as broad as the cortical shell, and connected with it by six
strong triangular radial beams, which are prolonged outside into pyramidal
spines, one-third as long as the shell diameter.
_Dimensions._--Diameter of the outer shell 0.2, pores 0.03, bars 0.002;
inner shell 0.06; length of the spines 0.06, breadth 0.02.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
12. _Hexalonche cristata_, n. sp.
Cortical shell thick walled, four times as broad as the medullary shell,
and covered with short conical spines arising from the nodal points of
elevated crests which form regular hexagonal frames around the
funnel-shaped circular pores. These are two to three times as broad as the
crested bars; eight to ten on the radius. Six spines three-sided pyramidal,
with strong prominent edges, about as long as the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.16 to 0.2, pores 0.01 to
0.015, bars 0.003 to 0.005; inner shell 0.04 to 0.05; length of the spines
0.08 to 0.12, basal breadth 0.01 to 0.03.
_Habitat._--Central Pacific, Station 266 to 274, depth 2350 to 2925
fathoms.
13. _Hexalonche serrata_, n. sp.
Cortical shell thick walled, four times as broad as the medullary shell,
with spiny surface. Pores regular circular, twice as broad as the bars,
five to seven on the radius, funnel-shaped, separated by hexagonal frames,
the sharp crests of which are serrated; at the nodal-points longer
bristle-shaped by-spines. Six main spines triangular prismatic, longer than
the diameter of the shell, twice as broad as one pore.
_Dimensions._--Diameter of the outer shell 0.15, pores 0.01, bars 0.005;
inner shell 0.04; length of the spines 0.2, breadth 0.02.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
14. _Hexalonche anaximenis_, n. sp. (Pl. 25, fig. 5).
Cortical shell thin walled, twice as broad as the medullary shell, and
covered with short conical by-spines. Pores regular circular, twice as
broad as the bars; five to six on the radius. Circular pores of the
medullary shell one-third as broad. Radial main spines conical, nearly as
long as the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.1, pores 0.01, bars 0.005;
inner shell 0.05; length of the spines 0.04, basal breadth 0.015.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
{184}15. _Hexalonche aspera_, n. sp.
Cortical shell thin walled, three times as broad as the medullary shell,
and covered with short conical spines. Pores regular circular, four to six
times as broad as the bars; eight to ten on the radius. Radial spines
conical, about as long as the diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.12, pores 0.08, bars 0.0015;
inner shell 0.04; length of the spines 0.1, basal breadth 0.02.
_Habitat._--South Pacific, Station 300, depth 1375 fathoms.
16. _Hexalonche castanella_, n. sp.
Cortical shell thick walled, five times as broad as the medullary shell,
and covered with numerous short conical spines. Pores regular circular,
twice as broad as the bars; ten to twelve on the radius. Radial spines
triangular pyramidal, about as long as the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.22, pores 0.01, bars 0.005;
inner shell 0.045; length of the spines 0.12, basal breadth 0.02.
_Habitat._--North Atlantic, Station 353, depth 3125 fathoms.
Subgenus 3. _Hexalonchilla_, Haeckel.
_Definition._--Pores of the cortical shell irregular, of unequal size or
form; surface smooth, without radial by-spines (other than the six main
spines).
17. _Hexalonche hexacantha_, Haeckel.
_Haliomma hexacanthum_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 35, Taf. iv. fig. 5.
_Haliomma hexacanthum_, Haeckel, 1862, Monogr. d. Radiol., p. 430.
Cortical shell thin walled, smooth, with irregular polygonal pores
(commonly hexagonal or pentagonal), two to three times as broad as the
bars; eight to ten on the radius. Medullary shell one quarter as broad,
connected with the former by six thin radial beams which are prolonged
outside into six triangular pyramidal spines (not quadrangular, as Müller
describes), longer than the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.2, pores 0.01 to 0.015, bars
0.005; inner shell 0.05; length of the spines 0.15, basal breadth 0.015.
_Habitat._--Mediterranean (Messina, Nice, Genoa).
18. _Hexalonche geometrica_, n. sp.
Cortical shell thick walled, smooth, with very peculiar geometrical
formation of its network, the pores of which are of very different size and
form, but highly regular disposition. Each of the six {185}triangular
spines is surrounded at the base by three small roundish pores (between the
three wings of its base), and further by a coronal of six very large pores,
three of which are pentagonal, and the other three (alternating)
heptagonal. The six basal coronals are separated by irregular smaller
pores. Medullary shell thin walled, with regular hexagonal pores (three on
the radius) and thin bars, connected with the outer shell by six thin
triangular prismatic radial beams, which are prolonged outside into short
pyramidal spines (half as long as the radius).
_Dimensions._--Diameter of the outer shell 0.2, thirty-six larger pores of
the coronals 0.03 to 0.04, smaller pores between them 0.01 to 0.02, bars
0.005; inner shell 0.05 (with pores of 0.008); length of the spines 0.05,
basal breadth 0.03.
_Habitat._--South Atlantic, off Buenos Ayres, Station 323, depth 1900
fathoms.
19. _Hexalonche pythagoræa_, n. sp. (Pl. 22, fig. 1).
Cortical shell thick walled, smooth, three times as broad as the medullary
shell. Pores irregular roundish, twice to eight times as broad as the bars,
of very different size; usually in the space between every three spines are
three or six larger pores, separated by numerous smaller pores (often the
disposition of the larger pores is much more regular than in the figured
specimen). Medullary shell with regular circular pores, connected with the
outer by six very thin radial beams, which are prolonged outside into six
short triangular pyramidal spines about as long and broad as the half
radius.
_Dimensions._--Diameter of the outer shell 0.12, pores 0.008 to 0.03, bars
0.004; inner shell 0.04; length of the spines 0.04, basal breadth 0.03.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
20. _Hexalonche aristarchi_, n. sp. (Pl. 22, fig. 3).
Cortical shell thin walled, smooth, four times as broad as the medullary
shell. Pores irregular polygonal, of very variable size and form, twice to
six times as broad as the bars; six to ten on the radius. Medullary shell
with regular hexagonal pores, connected with the outer by six very thin
radial beams, which are prolonged outside into six triangular pyramidal
spines, nearly as long as the radius.
_Dimensions._--Diameter of the outer shell 0.1, pores 0.005 to 0.02, bars
0.003; inner shell 0.025; length of the spines 0.05, basal breadth 0.01.
_Habitat._--North Pacific, Station 241, depth 2300 fathoms.
21. _Hexalonche ekphantæa_, n. sp.
Cortical shell thin walled, smooth, four times as broad as the medullary
shell. Pores irregular roundish, of very variable size and form, twice to
six times as broad as the bars, ten to fifteen on the radius. Six spines
cylindro-conical, longer than the diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.2, pores 0.004 to 0.012, bars
0.002; inner shell 0.05; length of the spine 0.3, basal breadth 0.01.
_Habitat._--Indian Ocean, Sunda Strait, surface, Rabbe.
{186}Subgenus 4. _Hexalonchusa_, Haeckel.
_Definition._--Pores of the cortical shell irregular, of different size or
form; surface covered with numerous conical or bristle-shaped, radial
by-spines.
22. _Hexalonche philosophica_, n. sp. (Pl. 22, fig. 4).
Cortical shell thin walled, covered with short conical spines, three times
as broad as the medullary shell. Pores irregular polygonal, or more
roundish, twice to six times as broad as the bars; six to eight on the
radius. Inner shell of the same structure, pores three times smaller,
connected with the outer by six very thin radial beams, which are prolonged
outside into six strong, triangular pyramidal spines, as long as the
radius. (Similar to _Hexalonche anaximandri_, Pl. 22, fig. 5, but different
in the irregular network and the shorter by-spines.)
_Dimensions._--Diameter of the outer shell 0.11, pores 0.005 to 0.015, bars
0.0025; inner shell 0.04; length of the spines 0.06, breadth 0.02.
_Habitat._--North Atlantic, Færöe Channel, John Murray; Iceland, Krabbe,
surface.
23. _Hexalonche seleuci_, n. sp.
Cortical shell thick walled, covered with numerous short, bristle-shaped
spines. Pores of very different size and form, and of a peculiar,
subregular disposition, similar to those of _Hexalonche geometrica_ (though
in this case more regular). Each of the six triangular main spines (which
reach nearly the length of the radius) is surrounded at the base by three
small roundish pores, and these are further supplemented by a coronal of
six very large polygonal pores; the six coronals are separated by irregular
rows of smaller pores. Inner shell equal to one-third of the outer. Six
main spines pyramidal, as long as the radius.
_Dimensions._--Diameter of the outer shell 0.16, larger pores 0.03 to 0.04,
smaller pores 0.01 to 0.02, bars 0.05 to 0.01; inner shell 0.05; length of
the spines 0.08, basal breadth 0.03.
_Habitat._--North Atlantic, Station 354, surface.
24. _Hexalonche sexaculeata_, Haeckel.
_Haliomma sexaculeatum_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 87, Taf.
i. fig. 8.
Cortical shell thick walled, twice as broad as the medullary shell, and
covered with short conical spines. Pores irregular polygonal (mostly
hexagonal), twice to three times as broad as the bars; six to eight on the
radius. Six spines triangular-pyramidal (not quadrangular), somewhat longer
than the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.11, pores 0.06 to 0.08, bars
0.03; inner shell 0.06; length of the spines 0.07, basal breadth 0.015.
_Habitat._--Fossil in Tertiary rocks of Sicily, Grotte, Caltanisetta.
{187}25. _Hexalonche heracliti_, n. sp. (Pl. 22, fig. 7).
Cortical shell thick walled, covered with bunches of small spines, each
bunch at the nodule point between every three pores composed of four to
eight conical spinules. Pores irregular roundish, twice to four times as
broad as the bars; four to six on the radius. Inner shell equal to
one-third of the outer, connected with it by six thin radial beams, which
are prolonged outside into six strong triangular spines about as long as
the radius.
_Dimensions._--Diameter of the outer shell 0.15, pores 0.015 to 0.03, bars
0.08; inner shell 0.05; length of the spines 0.06, basal breadth 0.02.
_Habitat._--Indian Ocean, Madagascar, Rabbe, surface.
26. _Hexalonche xenophanis_, n. sp.
Cortical shell thin walled, covered with numerous short conical spines,
four times as broad as the medullary shell. Pores irregular circular, twice
to eight times as broad as the bars; five to seven on the radius. Six
spines conical or more cylindrical, as long as the diameter of the shell or
longer.
_Dimensions._--Diameter of the outer shell 0.16 to 0.24, pores 0.01 to
0.04, bars 0.005; inner shell 0.04 to 0.06; length of the spines 0.2 to
0.3, breadth 0.02.
_Habitat._--Central Pacific, Stations 266 to 272, surface.
27. _Hexalonche setosa_, n. sp.
Cortical shell thin walled, covered with numerous bristle-shaped spines,
half as long as the six main spines. Pores irregular roundish, twice to
five times as broad as the bars; ten to twelve on the radius. Inner shell
equal to one-fifth of the outer. Six spines conical, as long as the radius.
_Dimensions._--Diameter of the outer shell 0.25, pores 0.008 to 0.02, bars
0.004; inner shell 0.05; length of the spines 0.12, basal breadth 0.03.
_Habitat._--South Pacific, Station 291, surface.
28. _Hexalonche hystricina_, n. sp. (Pl. 25, fig. 6).
Cortical shell thick walled, covered with numerous bristle-shaped spines,
half as long as the six main spines. Pores irregular roundish, twice to
four times as broad as the bars; five to seven on the radius. Medullary
shell with very small circular pores, one-fourth of the cortical shell,
connected with it by six thin prismatic radial beams, which are prolonged
outside into six strong, short, three-sided pyramidal, cuspidated spines,
only half as long as the radius of the outer shell.
_Dimensions._--Diameter of the outer shell 0.2, pores 0.015 to 0.03, bars
0.008; inner shell 0.05; length of the spines 0.05, basal breadth 0.02.
_Habitat._--Indian Ocean, Sunda Strait, surface, Rabbe.
{188}Genus 76. _Hexancistra_,[106] Haeckel, 1881, Prodromus, p. 451.
_Definition._--#Cubosphærida# with two concentric lattice-spheres and six
branched spines of equal size.
The genus _Hexancistra_ differs from its ancestral form, _Hexalonche_, in
the ramification of the six radial spines. These are very different in the
two subgenera; in _Hexancora_ each spine bears only three simple lateral
branches, while in _Hexapitys_ there are three rows of verticillate lateral
branches on each spine.
Subgenus 1. _Hexancora_, Haeckel.
_Definition._--Each radial spine with three simple lateral branches only
(one branch from each edge of the triangular spine).
1. _Hexancistra tricuspis_, n. sp. (Pl. 22, fig. 9).
Cortical shell thin walled, covered with short conical by-spines, three
times as broad as the medullary shell; its pores regular circular, three
times as broad as the bars; ten to twelve on the radius. Pores of the
medullary shell half as large, also regular circular. The two shells
connected by six thin prismatic radial beams, which are prolonged outside
into six very stout main spines, three-sided prismatic, as long as the
shell diameter, with three thin wing-like edges. Each edge at the distal
end prolonged into a strong curved lateral branch.
_Dimensions._--Diameter of the outer shell 0.13, inner 0.4; cortical pores
0.01, bars 0.003; medullary pores 0.005, bars 0.003; length of the six
spines 0.13, breadth 0.02.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
2. _Hexancistra ancorata_, n. sp.
Cortical shell thick walled, smooth, twice as broad as the medullary shell;
its pores regular circular, twice as broad as the bars; six to eight on the
radius. Six radial spines, three-sided prismatic, as long as the shell
radius, with three recurved lateral branches at the distal end like the
three teeth of an anchor.
_Dimensions._--Diameter of the outer shell 0.1, inner 0.05; cortical pores
0.006, bars 0.003; length of the six spines 0.05, breadth 0.02.
_Habitat._--South Pacific, Station 296, depth 1825 fathoms.
3. _Hexancistra triserrata_, n. sp. (Pl. 22, fig. 10).
Cortical shell thin walled, thorny, twice to three times as broad as the
medullary shell; the two shells connected by six strong triangular beams.
Inner shell spherical, with very small, regular, circular {189}pores; ten
to twelve on the half meridian. Bars as broad as the pores. Outer shell
regularly octahedral, with eight triangular perfectly regular even faces,
separated by eight prominent edges; the meshes circular, regular, about
twelve to fourteen on the half meridian, two to three times as broad as the
bars between them. Six strong radial spines, about as long as the diameter
of the outer shell, three-sided prismatic, cuspidate; their three edges
prominent, serrate, spirally twisted. Each spine bears about its middle
three strong flattened lateral branches, nearly perpendicular to it, not
serrated, and slightly curved.
_Dimensions._--Diameter of the outer shell 0.13, inner 0.045; pores of the
former 0.01, of the latter 0.004; length of the spine 0.12, breadth 0.014.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
4. _Hexancistra quadricuspis_, n. sp. (Pl. 22, fig. 11).
Cortical shell thin walled, covered with short bristle-shaped by-spines,
three and a half times as broad as the medullary shell. Pores of the latter
regular circular, small; pores of the former three to six times as large,
very irregular, roundish, double-edged. Six radial spines, three-sided
prismatic, about as long as the shell diameter, with three wing-like,
slightly twisted edges, which are prolonged towards the distal end into
three curved horn-shaped branches.
_Dimensions._--Diameter of the outer shell 0.17, inner 0.05; cortical pores
0.01 to 0.03, bars 0.005; medullary pores 0.003, bars 0.001; length of the
spines 0.15, breadth 0.013.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
Subgenus 2. _Hexapitys_, Haeckel, 1881, Prodromus, p. 451.
_Definition._--Each radial spine with three rows of verticillate lateral
branches (a row arising from each edge of the spine).
5. _Hexancistra mirabilis_, n. sp. (Pl. 23, fig. 3).
_Hexapitys mirabilis_, Haeckel, 1881, Prodromus, p. 451.
Cortical shell very thin walled, three times as broad as the medullary
shell. Inner shell spherical, with very delicate, subregular hexagonal
meshes; seven to eight on the half diameter. Outer shell octahedral, with
irregular polygonal meshes of very different size; on the surface numerous
thin accessory radial spines, equal in length to its radius. Six main
spines, extremely long and stout, many times longer than the diameter of
the outer shell, nearly as broad as the radius of the inner shell,
three-sided prismatic, with sharp, prominent, spirally twisted edges; on
every edge a great number of thin lateral branches, arranged
perpendicularly to it, as long as the diameter of the outer shell, and
pinnated by ten to twenty pairs of delicate secondary spinules, biserial
and perpendicular to the primary branches. (In the figured specimen the
spherical central capsule, between both shells, was well preserved; its
nucleus nearly filled the medullary shell. The thick jelly-veil around it
was radially striped and octahedral.)
{190}_Dimensions._--Diameter of the outer shell 0.13, of the inner 0.05;
length of the spines 0.5 to 0.8 or more, breadth 0.02.
_Habitat._--Central Pacific, Station 271, surface.
Genus 77. _Hexaloncharium_,[107] n. gen.
_Definition._--#Cubosphærida# with two concentric lattice-spheres and six
simple spines of different sizes; one opposite pair larger than the two
others.
The genus _Hexaloncharium_ exhibits the same relation to its ancestral
form, _Hexalonche_, that _Hexastylarium_ bears to _Hexastylus_. Two
opposite spines of one pair are larger than the four others, and correspond
to the three axes of a quadratic crystal.
1. _Hexaloncharium octahedrum_, n. sp.
Cortical shell smooth, three to four times as broad as the spherical
medullary shell, each having regular circular pores, twice to three times
as broad as the bars. Form of the outer shell not a sphere, but a regular
octahedron, with eight congruent, equilateral triangular even faces. Two
opposite spines twice as long as the shell diameter, whilst the four others
are scarcely equal to it. Basal breadth of all six the same (three times as
large as one pore); form, three-sided prismatic, with cuspidate distal end.
(Similar to _Hexalonche octahedra_, Pl. 22, fig. 8, but distinct in the
unequal length of the spines.)
_Dimensions._--Diameter of the outer shell 0.16, inner 0.045; length of the
major spine 0.3, minor 0.12, basal breadth 0.03.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
2. _Hexaloncharium philosophicum_, n. sp.
Cortical shell spherical, covered with short conical by-spines, twice as
broad as the medullary shell; both with regular circular pores three to
four times as broad as the bars. Two major spines cylindrical, with conical
apex, three times as long as the four others, which are conical and about
as long as the shell radius; basal breadth of all six the same (equal to
one pore). Similar to _Hexalonche anaximenis_ (Pl. 25, fig. 5), but
distinct in the enormous prolongation of two opposite spines.
_Dimensions._--Diameter of the outer shell 0.12, inner 0.06; length of the
two major spines 0.2, of the four minor 0.06, basal breadth 0.02.
_Habitat._--Central Pacific, Station 267, depth 2700 fathoms.
{191}3. _Hexaloncharium hystricinum_, n. sp.
Cortical shell spherical, three times as broad as the medullary shell, and
densely covered with oblique bristle-shaped by-spines. Pores irregular
roundish. Two opposite major spines three-sided prismatic, longer than the
shell diameter; four minor spines pyramidal, scarcely half as long as the
shell radius. (Somewhat similar to _Hexalonche hystricina_, but distinct in
the prolongation of two major spines.)
_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; length of the
two major spines 0.2, four minor 0.03, basal breadth 0.02.
_Habitat._--South Pacific, Station 288, surface.
Genus 78. _Hexalonchidium_,[108] Haeckel, 1881, Prodromus, p. 451.
_Definition._--#Cubosphærida# with two concentric lattice-spheres and six
simple spines of different sizes in pairs; the two opposite spines of each
pair equal, the three pairs unequal.
The genus _Hexalonchidium_ exhibits the same relation to _Hexalonche_ that
_Hexastylidium_ bears to _Hexastylus_; the growth of the three spine-pairs
is different, whilst both spines of each pair are equal; they correspond
therefore to the three axes of a rhombic crystal.
1. _Hexalonchidium axonometrum_, n. sp.
Cortical shell thin walled, covered with short bristle-shaped by-spines,
twice as broad as the medullary shell; both with regular hexagonal meshes,
twice to three times as broad as the bars (inner meshes half as broad as
the outer). All three spine-pairs three-sided prismatic, of very different
length but of equal breadth (equal to three pores). Major spine-pair twice
as long as the shell diameter; middle pair about equal to the latter, minor
scarcely half as long. (Similar to _Hexalonche anaximandri_, Pl. 22, fig.
5, but distinct in the different length of the spines.)
_Dimensions._--Diameter of the outer shell 0.12, inner 0.06; length of the
major spines 0.25, middle 0.1, minor 0.04.
_Habitat._--Indian Ocean, Madagascar, surface, Rabbe.
Subfamily HEXACONTIDA,[109] Haeckel, 1881, Prodromus, pp. 449, 452.
_Definition._--#Cubosphærida# with three concentric, spherical, or
octahedral lattice-shells.
{192}Genus 79. _Hexacontium_, Haeckel,[110] 1881, Prodromus, p. 452.
_Definition._--Shell with three concentric lattice-spheres and six simple
spines of equal size.
The genus _Hexacontium_, the ancestral form of the Hexacontida, is probably
derived from _Hexalonche_ by duplication of the medullary shell. As in the
latter, all six spines are of equal size, opposite in pairs in the three
dimensive axes, and correspond therefore to the three equal axes of a
tesseral crystal.
Subgenus 1. _Hexacontanna_, Haeckel.
_Definition._--Pores of the cortical shell regular or subregular, of nearly
equal size and similar form; surface smooth, without radial spines or
papillæ (other than the six main spines).
1. _Hexacontium phænaxonium_, n. sp.
Cortical shell thin walled, smooth; its pores regular hexagonal, six to
nine times as broad as the bars; twelve to sixteen on the radius. Radial
proportion of the three spheres = 1 : 2 : 4. Both medullary shells of the
same structure as the cortical shell, only with smaller pores. The three
spheres connected by six thin radial beams, which are prolonged on the
outside into six strong triangular pyramidal spines, as long as the radius
of the cortical shell, and, at the base, as broad as one of its pores.
(Differs from _Hexastylus phænaxonius_ and from _Hexalonche phænaxonia_,
Pl. 21, fig. 3, in the larger size and the triple shell.)
_Dimensions._--Diameter of the outer sphere 0.2, middle 0.1, inner 0.05;
cortical pores 0.008, bars 0.0012; length of the spines 0.1.
_Habitat._--Central Pacific, Station 270, surface.
2. _Hexacontium axotrias_, n. sp. (Pl. 24, fig. 3).
Cortical shell thin walled, smooth; its pores regular circular, five to six
times as broad as the bars; eleven to thirteen on the radius. Radial
proportion of the three spheres = 1 : 3 : 8. Outer medullary shell with
hexagonal frames around the regular circular pores (five to six on the
radius). Inner medullary shell with simple small circular pores (three on
the radius). The two outer shells connected by six triangular prismatic
beams, which are prolonged outside to the length of the cortical radius or
more.
_Dimensions._--Diameter of the outer sphere 0.2, middle 0.07, inner 0.025;
cortical pores 0.016, bars 0.003; length of the spines 0.1 to 0.015, basal
breadth 0.02.
_Habitat._--North Pacific, Station 253, surface.
3. _Hexacontium hexactis_, Haeckel.
_Actinomma hexactis_, Stöhr, 1880, Palæontogr., vol. xxvi. p. 91, Taf.
ii. fig. 7.
Cortical shell thick walled, smooth, or a little rough. Pores regular
circular, of the same breadth as the bars; five to seven on the radius.
Radial proportion of the three spheres {193}= 1 : 3 : 6. Both medullary
shells of the same structure, but with smaller pores. Six spines triangular
pyramidal, nearly as long as the diameter of the outer shell, three times
as broad at the base as one pore.
_Dimensions._--Diameter of the outer sphere 0.1, middle 0.05, inner 0.016;
cortical pores and bars 0.008; length of the spines 0.08, basal breadth
0.025.
_Habitat._--Fossil in Tertiary rocks of Sicily, Grotte, Stöhr.
4. _Hexacontium lævigatum_, n. sp. (Pl. 24, fig. 6).
Cortical shell thick walled, quite smooth. Pores regular circular, with
double margins, eight to ten on the radius, of the same breadth as the
smooth bars. Radial proportion of the three spheres = 1 : 2 : 6. All three
spheres connected by six very thin radial beams, which are prolonged
outside into six short, stout, triangular, pyramidal spines, half as long
as the radius of the outer shell.
_Dimensions._--Diameter of the outer shell 0.13, middle 0.04, inner 0.02;
cortical pores and bars 0.008; length of the spines 0.04, basal breadth
0.02.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
5. _Hexacontium triplosphærium_, n. sp.
Cortical shell thick walled, smooth. Pores regular circular, three times as
broad as the bars; ten to twelve on the radius. Radial proportion of the
three spheres = 1 : 3 : 10. Six spines conical, about as long as the radius
of the cortical shell.
_Dimensions._--Diameter of the outer shell 0.16, middle 0.05, inner 0.016;
cortical pores 0.012, bars 0.004; length of the spines 0.07, basal breadth
0.02.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
6. _Hexacontium octahedrum_, n. sp.
Cortical shell a regular octahedron, thin walled, with twelve more or less
rounded edges (between the spine-bases) and with smooth surface; its pores
regular circular, five to seven on the radius, four times as broad as the
bars. Radial proportion of the three shells = 1 : 3 : 9. Both medullary
shells spherical, with very small circular pores. Six inner bars very thin;
six outer spines (their prolongations) triangular pyramidal, as long as the
radius of the outer shell. (Differs from _Hexalonche octahedra_, Pl. 22,
fig. 8, almost solely in the duplication of the medullary shell.)
_Dimensions._--Diameter of the outer shell 0.12, middle 0.04, inner 0.013.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
7. _Hexacontium circumtextum_, n. sp. (Pl. 25, figs. 7, 7_a_).
Cortical shell double, enclosing a simple medullary shell. Radial
proportion of the three spheres = 3 : 10 : 12. Inner cortical shell very
thick walled, with regular circular, double-edged pores, four times as
broad as the bars; seven to nine on the radius. From each nodal-point
between {194}every six pores arises a small, bristle-shaped, radial spine,
as long as the diameter of one pore. The distal ends of all these spines
are connected by very delicate tangential threads, and consequently form by
their attachment an outer cortical shell, with regular hexagonal meshes and
smooth surface. Six main spines short, three-sided prismatic, scarcely as
long as half the radius of the outer shell.
_Dimensions._--Diameter of the outer shell 0.12, middle 0.1, inner 0.03;
pores of the middle shell 0.004, bars 0.001; length of the spines 0.025,
basal breadth 0.01.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
Subgenus 2. _Hexacontella_, Haeckel.
_Definition._--Pores of the cortical shell regular or subregular, of nearly
equal size and similar form; surface covered with numerous conical or
bristle-shaped, radial spines (other than the six main spines).
8. _Hexacontium hexagonale_, n. sp.
Cortical shell thin walled, bristly, with very delicate network; its pores
regular hexagonal, twelve to sixteen on the radius, ten to twelve times as
broad as the thin thread-like bars. At each nodal-point of the network
(between every three meshes) arises a bristle-shaped, radial spine, as long
as the diameter of one mesh. Six main spines hexagonal, as long as the
radius of the outer shell, as broad at its base as one mesh. Radial
proportion of the three spheres = 1 : 2 : 4. Pores of both medullary shells
also regular hexagonal, but much smaller, in the middle shell eleven to
twelve, in the inner, six to seven on the half meridian.
_Dimensions._--Diameter of the outer shell 0.12, of the middle 0.06, of the
inner 0.03; meshes of the outer shell 0.008; length of the six spines 0.05,
basal thickness 0.008.
_Habitat._--Indian Ocean, Ceylon, surface, Haeckel.
9. _Hexacontium favosum_, n. sp. (Pl. 24, figs. 2, 2_a_).
Cortical shell very thick walled, spiny, with regular, honeycomb-like
network; its meshes funnel-shaped, with circular inner, hexagonal outer
aperture, twice as broad as the bars; five to seven on the radius. Between
every three meshes (at each corner of the hexagon) arises a short radial
thorn, not so long as the thickness of the shell-wall. Six radial spines
very short and stout, three-sided pyramidal, scarcely half so long as the
radius of the outer shell. Radial proportion of the three spheres =
1 : 2 : 5. Pores of both medullary shells regular, circular, about as broad
as the bars, six to eight on the half meridian.
_Dimensions._--Diameter of the outer shell 0.1 to 0.12, of the middle 0.04
to 0.05, of the inner 0.02; meshes of the outer shell 0.008; length of the
six spines 0.2 to 0.3, basal breadth 0.015.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
10. _Hexacontium sceptrum_, n. sp. (Pl. 24, figs. 1, 1_a_).
Cortical shell thick walled, spiny, with regular, honeycomb-like network;
its meshes funnel-shaped, with circular inner, hexagonal outer aperture,
three to four times as broad as the bars; {195}five to six on the radius.
Between every three meshes arises a short radial thorn, as long as the
thickness of the shell-wall. Six radial spines sceptre-shaped, six-sided,
somewhat constricted towards their middle part, strong, as long as the
radius of the outer shell, as broad as one of its meshes. Radial proportion
of the three spheres = 1 : 2 : 6. Pores of the two inner shells regular
hexagonal, with thin bars, six to eight on the half meridian (fig. 1_a_).
_Dimensions._--Diameter of the outer shell 0.13, of the middle 0.04, of the
inner 0.02; pores of the outer shell 0.01, of the middle 0.008, of the
inner 0.004; length of the six spines 0.06, basal breadth 0.015.
_Habitat._--Equatorial Atlantic, Station 347, surface.
11. _Hexacontium prionacanthum_, n. sp. (Pl. 24, figs. 7, 7_a_).
Cortical shell thick walled, thorny; its pores regular circular, with
elevated hexagonal frames six to nine on the radius, twice as broad as the
crest-shaped bars. At each nodal-point of the hexagon arises one short
conical papilla or thorn. Radial proportion of the three spheres =
1 : 3 : 10. Pores of both medullary shells much smaller, regular circular.
Six main spines three-sided prismatic, longer than the radius of the outer
shell, as broad as one of its meshes; their three edges serrated, with ten
to twelve teeth.
_Dimensions._--Diameter of the outer shell 0.15, middle 0.045, inner 0.015;
cortical pores 0.01, bars 0.005; length of the spines 0.1, breadth 0.012.
_Habitat._--West Tropical Pacific, Station 225, depth 4475 fathoms.
12. _Hexacontium clavigerum_, n. sp. (Pl. 23, fig. 5).
Cortical shell very thick walled, thorny; its pores regular circular,
hexagonally framed, three times as broad as the bars, nine to twelve on the
radius; between them short conical papillæ or thorns arising at the
nodal-points. Radial proportion of the three spheres = 1 : 2 : 5. Outer
medullary shell with regular circular, much smaller pores; connected with
the cortical shell by numerous (twenty to thirty) thin radial beams. Six
main spines very stout, club-shaped, scarcely as long as the radius of the
outer shell, three times as broad as one of its pores, three-sided, with
three to four teeth on each edge.
_Dimensions._--Diameter of the outer shell 0.2, of the middle 0.08, of the
inner 0.04; cortical pores 0.012, bars 0.004; length of the six spines
0.08, breadth 0.03.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
13. _Hexacontium floridum_, n. sp. (Pl. 24, fig. 4).
Cortical shell papillose, thick walled. Pores regular, six-lobed, four
times as broad as the bars, five to seven on the radius; each pore with six
(sometimes also five or seven) concave indentations or lobules; between the
pores at the nodal-points arise short conical papillæ or thorns. Radial
proportion of the three spheres = 1 : 2 : 3. Radial main spines
pommel-shaped, three-sided prismatic, longer than the radius of the outer
shell, two to three times as broad as one pore.
{196}_Dimensions._--Diameter of the outer shell 0.12, middle 0.06, inner
0.03; cortical pores 0.012, bars 0.003; length of the six spines 0.08,
breadth 0.03.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
14. _Hexacontium hexaconicum_, n. sp.
Cortical shell spiny, thick walled. Pores regular circular, of the same
breadth as the bars, ten to twelve on the radius; between them long
bristle-shaped by-spines, half as long as the six main spines. Radial
proportion of the three spheres = 1 : 3 : 9. Six main spines conical, as
long as the radius of the outer shell, four times as broad at the base as
one pore.
_Dimensions._--Diameter of the outer shell 0.18, middle 0.06, inner 0.02;
cortical pores and bars 0.005; length of the spines 0.1, basal breadth
0.02.
_Habitat._--Antarctic Sea, Station 157, depth 1950 fathoms.
15. _Hexacontium asteracanthion_, Haeckel.
_Haliomma asteracanthion_, Haeckel, 1860, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 816.
_Actinomma asteracanthion, Haeckel_, 1862, Monogr. d. Radiol., p. 441,
Taf. xxiii. figs. 5, 6.
Cortical shell thin walled, spiny; its pores circular, without hexagonal
frame (as a rule very regular, but in other specimens more or less
irregular), often very variable in size, three to six times as broad as the
bars, commonly seven to eight on the radius. Radial proportion of the three
spheres = 1 : 2 : 4, or sometimes 1 : 3 : 8. Pores of the two inner shells
also circular, but much smaller; those of the middle shell about half as
broad, those of the inner shell one-fourth to one-sixth as broad as the
pores of the outer shell. Six radial spines strong, three-sided prismatic,
about as long as (or somewhat longer than) the radius of the outer shell,
as broad as one of its large meshes. Accessory spines very numerous and
very thin, bristle-like, usually half as long as the six main spines. (For
the variability of this common species compare my Monograph, p. 442.)
_Dimensions._--Diameter of the outer shell 0.1 to 0.12, of the middle 0.04
to 0.06, of the inner 0.02 to 0.03; cortical pores 0.005 to 0.01; length of
the six spines 0.06 to 0.08.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.
Subgenus 3. _Hexacontosa_, Haeckel.
_Definition._--Pores of the cortical shell irregular, of different size or
form; surface smooth, without radial by-spines or papillæ (other than the
six main spines).
16. _Hexacontium axophænum_, n. sp.
Cortical shell thin walled, smooth. Pores irregular polygonal, three to
nine times as broad as the bars; seven to ten on the radius. Radial
proportion of the three spheres = 1 : 3 : 8. Both {197}medullary shells
with smaller, irregular roundish pores. Six spines three-sided pyramidal,
longer than the radius of the outer shell, one to two times as broad as one
larger pore.
_Dimensions._--Diameter of the outer shell 0.12, middle 0.045, inner 0.015;
cortical pores 0.006 to 0.018, bars 0.002; length of the spines 0.06 to
0.12, basal breadth 0.02 to 0.03.
_Habitat._--Central Pacific, Stations 266 to 272, at various depths.
17. _Hexacontium polygonale_, n. sp.
Cortical shell thick walled, smooth. Pores irregular roundish, with
polygonal frames, two to four times as broad as the bars; eight to twelve
on the radius. Radial proportion of the three spheres = 1 : 3 : 10. Six
spines pyramidal, nearly as long as the diameter of the outer shell, with
six to nine prominent edges (along the corner number of the polygonal
meshes).
_Dimensions._--Diameter of the outer shell 0.2, middle 0.06, inner 0.02;
cortical pores 0.008 to 0.016, bars 0.004; length of the spines 0.16 to
0.18, basal breadth 0.02.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
18. _Hexacontium antarcticum_, n. sp.
Cortical shell thin walled, smooth, with irregular roundish pores, eight to
ten on the radius, two to four times as broad as the bars. Radial
proportion of the three spheres = 1 : 3 : 9. Both medullary shells with
smaller roundish irregular pores. Six spines conical, pyramidal at their
origin, about as long as the radius, as broad as one larger mesh.
_Dimensions._--Diameter of the outer shell 0.18, middle 0.06, inner 0.02;
cortical pores 0.006 to 0.012, bars 0.003; length of the spines 0.1, basal
breadth 0.12.
_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.
Subgenus 4. _Hexacontura_, Haeckel.
_Definition._--Pores of the cortical shell irregular, of different size or
form; surface covered with numerous conical papillæ or bristle-shaped,
radial by-spines (other than the six main spines).
19. _Hexacontium papillosum_, n. sp. (Pl. 24, fig. 5).
Cortical shell thick walled, papillose. Pores irregular roundish, often
somewhat lobed, five to six on the radius, two to four times as broad as
the bars. Radial proportion of the three spheres = 1 : 2.5 : 5. Both
medullary shells with subregular circular pores (inner much smaller). Six
radial spines short and stout, pommel or club shaped, with three prominent
wings, about as long as the shell radius, and as broad as the medullary
shell.
_Dimensions._--Diameter of the outer shell 0.1, middle 0.05, inner 0.02,
cortical pores 0.006 to 0.012, bars 0.003; length of the spines 0.05, bars
0.02.
_Habitat._--Central Pacific, Stations 266 to 272, at various depths.
{198}20. _Hexacontium gladiatum_, n. sp. (Pl. 25, fig. 8).
Cortical shell very thick walled, spiny, with irregular network; its meshes
roundish, two to five times as broad as the bars, of very different size,
ten to fifteen on the half meridian. Bars between them very strong,
three-sided prismatic, armed with a great number of small thorns, and with
large spines at the nodal-points between every three meshes. Radial
proportion of the three spheres = 1 : 3 : 12. Six strong radial main spines
three-sided prismatic, with three prominent, somewhat contorted wings,
acute, broader than the diameter of the inner shell and as long as the
diameter of the outer shell. These six main spines are situated in the same
three dimensive axes as the six thin radial beams connecting the two
medullary shells. But the six radial beams which connect the middle with
the outer shell alternate with the former and lie in three other dimensive
axes,--a very rare and remarkable disposition.
_Dimensions._--Diameter of the outer shell 0.2, middle 0.05, inner 0.016;
cortical pores 0.01 to 0.03, bars 0.006; length of the six spines 0.2,
breadth 0.02 to 0.03.
_Habitat._--Tropical Atlantic, Station 342, depth 1445 fathoms.
21. _Hexacontium setosum_, n. sp.
Cortical shell thin walled, with numerous bristle-shaped, simple, radial
by-spines of variable length. Pores irregular roundish, five to seven on
the radius, two to eight times as broad as the bars. Radial proportion of
the three spheres = 1 : 3 : 9. Main spines three-sided pyramidal, as long
as the radius.
_Dimensions._--Diameter of the outer shell 0.1 to 0.015, middle 0.035 to
0.05, inner 0.013 to 0.016; cortical pores 0.01 to 0.03, bars 0.003 to
0.004; length of the six spines 0.05 to 0.08, basal breadth 0.012 to 0.015.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific, surface; also
fossil in Barbados.
22. _Hexacontium furcatum_, n. sp.
Cortical shell thin walled, covered with numerous thin, bristle-shaped
by-spines, which are forked and nearly as long as the main spines. Pores
irregular roundish, eight to ten on the radius, two to eight times as broad
as the bars. Radial proportion of the three spheres = 1 : 2.5 : 10. Main
spines triangular pyramidal, shorter then the radius.
_Dimensions._--Diameter of the outer shell 0.18, middle 0.045, inner 0.018;
cortical pores 0.005 to 0.015, bars 0.002; length of the six spines 0.07,
basal breadth 0.015.
_Habitat._--North Atlantic, Station 354, surface.
23. _Hexacontium drymodes_, Haeckel.
_Actinomma drymodes_, Haeckel, 1862, Monogr. d. Radiol., p. 442, Taf.
xxiv. fig. 9.
Cortical shell thin walled, covered with numerous thin, bristle-shaped
spines, which are double forked and half as long as the main spines. Pores
irregular roundish, eight to ten on the radius, {199}two to eight times as
broad as the bars. Radial proportion of the three spheres = 1 : 2 : 4. Main
spines three-sided prismatic, with prominent, often somewhat contorted
edges, at the distal end cuspidated; longer than the radius of the outer
shell.
_Dimensions._--Diameter of the outer shell 0.15, middle 0.07, inner 0.035;
cortical pores 0.01 to 0.03, bars 0.04; length of the six spines 0.11,
basal breadth 0.03.
_Habitat._--Mediterranean (Messina), surface; Canary Islands (Lanzerote);
Haeckel.
24. _Hexacontium periplectum_, n. sp.
Cortical shell double, enclosing a simple medullary shell. Radial
proportion of the three shells = 1 : 4 : 5. Inner cortical shell thick
walled, with irregular roundish pores, two to eight times as broad as the
bars; five to seven on the radius. Numerous radial spines, arising from it,
are connected below their distal ends (at equal distances from the centre)
by delicate branched threads, and so form an outer, irregular, thin,
cortical shell, with spiny surface. Six main spines three-sided pyramidal,
about as long as the radius.
_Dimensions._--Diameter of the outer shell 0.22, middle 0.2, inner 0.045;
cortical pores (of both outer shells) 0.01 to 0.03, bars 0.001 to 0.005;
length of the spines 0.1, basal breadth 0.02.
_Habitat._--North Pacific, Station 241, surface.
Genus 80. _Hexadendron_,[111] Haeckel, 1881, Prodromus, p. 452.
_Definition._--#Cubosphærida# with three concentric lattice-spheres and six
branched spines of equal size.
The genus _Hexadendron_ differs from _Hexacontium_ in the ramification of
the six dimensive spines, and from the similar _Hexancistra_ in the
duplication of the medullary shell. As in the latter instance, each spine
can bear either three simple lateral branches or three rows of pinnate
lateral branches.
1. _Hexadendron quadricuspis_, n. sp.
All three shells spherical, with radial proportion = 1 : 2 : 6. Pores of
both medullary shells regular circular, twice as broad as the bars. Pores
of the cortical shell irregular roundish, four to six times as broad as the
bars; surface a little thorny. Six radial spines prismatic, with three
prominent wing-like edges, which are prolonged below the distal end in
three curved lateral branches. (Differs from _Hexalonche quadricuspis_, Pl.
22, fig. 11, mainly in the double medullary shell.)
_Dimensions._--Diameter of the outer shell 0.15, middle 0.05, inner 0.025;
length of the spines 0.12, breadth 0.01.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
{200}2. _Hexadendron bipinnatum_, n. sp. (Pl. 23, fig. 1).
All three shells regular octahedral, with very delicate network of
irregular polygonal meshes, and very thin, thread-like bars between them;
their radial proportion = 1 : 2.5 : 7.5. Surface of the cortical shell
covered with numerous bristle-shaped by-spines, as long as the radius. Six
main spines very large, three-sided prismatic, with three rows of pinnate,
lateral branches, on the three wing-like, spirally twisted edges (similar
to those of _Hexancistra mirabilis_, p. 189, Pl. 23, fig. 3).
_Dimensions._--Diameter of the outer shell 0.12, middle 0.04, inner 0.016.
_Habitat._--Central Pacific, Station 272, surface.
Genus 81. _Hexacontarium_,[112] n. gen.
_Definition._--#Cubosphærida# with three concentric lattice-spheres and six
simple spines of different size; one opposite pair larger than the two
others.
The genus _Hexacontarium_ exhibits to its ancestral form _Hexacontium_ the
same relation that _Hexaloncharium_ bears to _Hexalonche_; the former is
developed from the latter by duplication of the medullary shell. As two
opposite spines of one pair are larger than the four others, they
correspond to the three axes of a quadratic crystal.
1. _Hexacontarium dentatum_, n. sp.
Cortical shell with regular circular, hexagonally framed pores, twice as
broad as the bars, with smooth surface. Radial proportion of the three
spheres = 1 : 2 : 5. Six radial spines three-sided prismatic, half as broad
as the inner medullary shell, with three dentated edges. Two opposite major
spines longer than the shell diameter; four other minor spines only half as
long as the radius. (Similar to _Hexacontium clavigerum_, Pl. 23, fig. 5,
but distinct by the prolongation of the spines of one axis.)
_Dimensions._--Diameter of the outer shell 0.15, middle 0.06, inner 0.03;
length of the major spines 0.2, minor 0.04.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
2. _Hexacontarium clavatum_, n. sp.
Cortical shell covered with short conical by-spines and irregular roundish
pores, three to four times as broad as the bars. Radial proportion of the
three spheres = 1 : 3 : 8. Six radial spines three-sided prismatic, at the
distal end club-shaped; two major spines three times as long as the four
others, which are equal to the shell radius.
_Dimensions._--Diameter of the outer shell 0.16, middle 0.06, inner 0.02.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
{201}Subfamily HEXACROMYIDA,[113] Haeckel, 1881, Prodromus, pp. 449, 453.
_Definition._--#Cubosphærida# with four concentric spherical
lattice-shells.
Genus 82. _Hexacromyum_,[114] Haeckel, 1881, Prodromus, p. 453.
_Definition._--#Cubosphærida# with four concentric lattice-spheres and six
simple spines of equal size.
The genus _Hexacromyum_ possesses four concentric, spherical, or octahedral
lattice-shells; two inner medullary shells within the central capsule, two
outer cortical outside it. The four spheres are connected by six radial
beams, which are prolonged outside into simple spines of equal size,
opposite in pairs in the three dimensive axes. This genus can be derived
from _Hexacontium_ by duplication of the cortical shell.
1. _Hexacromyum elegans_, n. sp. (Pl. 24, fig. 9).
Shell composed of four concentric shells, with radial proportion =
1 : 2.5 : 7.5 : 10. First (innermost) shell with very small circular pores,
second shell with larger circular pores. Third shell (inner cortical shell)
with large, subregular, circular, hexagonally framed pores (eight to nine
on the radius), twice as broad as the bars; from the elevated nodal-points
of the hexagonal frames (between every three pores) arise thin
bristle-shaped radial beams, which are united at the distal end by vaulted
branches forming the delicate fourth shell. Surface smooth. Radial spines
three-sided pyramidal, as long as the radius, as broad at the base as the
innermost shell.
_Dimensions._--Diameter of the four shells--(A) 0.02, (B) 0.05, (C) 0.15,
(D) 0.2; length of the six radial spines 0.1, basal breadth 0.02.
_Habitat._--Central Pacific, Station 271, surface.
2. _Hexacromyum quadrigatum_, n. sp.
Shell composed of four concentric shells, with radial proportion =
1 : 3 : 8 : 10. Structure of all four shells the same, with regular,
circular pores, twice to three times as broad as the bars; size of the
pores gradually increasing from the innermost to the outermost shell;
surface smooth. Radial spines three-sided pyramidal, as long as the radius,
half as broad at the base as the innermost shell.
_Dimensions._--Diameter of the four shells--(A) 0.025, (B) 0.08, (C) 0.20,
(D) 0.25; length of the spines 0.12, basal breadth 0.012.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
{202}3. _Hexacromyum arachnoides_, n. sp.
_Hexacromidium arachnoides_, Haeckel, 1881, Prodromus, p. 453.
Shell composed of four concentric shells, with radial proportion =
1 : 2 : 3 : 4. Innermost shell with regular, hexagonal meshes; the three
other shells with irregular, polygonal meshes; bars between the large
meshes in all four shells very thin, cobweb-like. Surface covered with thin
bristle-shaped by-spines, as long as the radius. Six radial main spines
three-sided prismatic, longer than the diameter of the whole shell.
_Dimensions._--Diameter of the four shells--(A) 0.08, (B) 0.16, (C) 0.24,
(D) 0.32; length of the spines 0.4, breadth 0.01.
_Habitat._--South Pacific, Station 300, depth 1375 fathoms.
4. _Hexacromyum octahedrum_, n. sp. (Pl. 23, fig. 2).
Shell composed of four concentric shells which are not spherical (as in the
three preceding species), but regular octahedral. Radial proportion =
1 : 2.5 : 6 : 9. Network in all four shells delicate, with irregular
polygonal meshes and thin bars; the thickness of the bars and size of the
meshes increasing from the innermost to the outermost shell. Six radial
spines three-sided prismatic, increasing slowly in breadth towards the
distal end, much longer than the shell diameter.
_Dimensions._--Diameter of the four shells--(A) 0.02, (B) 0.05, (C) 0.12,
(D) 0.18; length of the radial spines 0.2 to 0.3 and more, breadth 0.01.
_Habitat._--Central Pacific, Station 263, depth 2650 fathoms.
Subfamily HEXACARYIDA,[115] Haeckel, 1881, Prodromus, p. 454.
_Definition._--#Cubosphærida# with five or more concentric lattice-shells.
Genus 83. _Cubosphæra_,[116] n. gen.
_Definition._--#Cubosphærida# with five to six or more concentric
lattice-shells and six simple spines of equal size.
The genus _Cubosphæra_ is developed from the preceding _Hexacromyum_ by
further addition of the concentric lattice-shells, their number amounting
to five, six, or more. The innermost two of these are medullary shells, the
others being cortical shells. All are connected by six radial beams,
prolonged outside into six simple spines of equal size; these lie opposite
in pairs in three dimensive axes, corresponding to the three axes of a
cube.
{203}1. _Cubosphæra cubaxonia_, n. sp. (Pl. 24, fig. 8).
_Hexacromyon cubaxonium_, Haeckel, 1881, Prodrom. et Atlas.
Shell composed of five concentric spheres, with the radial proportion =
1 : 3 : 8 : 10 : 13. The two medullary shells with small regular, circular
pores of the same breadth as the bars. Inner cortical shell (third shell)
with large regular, circular pores, four times as broad as the bars,
hexagonally framed. From each hexagon-corner arises a thin bristle-shaped
radial by-spine, which at a fixed distance from the centre is united with
the middle cortical shell (fourth shell), which has very small circular
pores. The beginning of the fifth shell (outermost) is indicated by six
small reticula, produced by the six main spines at equal distances from the
centre. All five shells are united by six prismatic radial beams, ending
outside in pyramidal furrowed spines.
_Dimensions._--Diameter of the five shells--(A) 0.2, (B) 0.15, (C) 0.12,
(D) 0.045, (E) 0.015.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
2. _Cubosphæra concentrica_, n. sp.
Shell composed of six concentric spheres, with the radial proportion =
1 : 2 : 6 : 7.5 : 9 : 11. The two medullary shells with regular, circular
pores, twice as broad as the bars. The four cortical shells of the same
structure, with irregular, roundish pores, three to four times as broad as
the bars. The size of these pores and the breadth of their bars gradually
increase towards the smooth surface. All six shells are connected by six
thin three-sided prismatic radial beams, which are prolonged outside in six
stronger spines, angular pyramidal, with smooth edges, as long as the shell
radius.
_Dimensions._--Diameter of the six shells--(A) 0.02 (B) 0.04, (C) 0.12, (D)
0.15, (E) 0.18, (F) 0.22.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
Genus 84. _Hexacaryum_,[117] Haeckel, 1881, Prodromus, p. 454.
_Definition._--#Cubosphærida# with five to six or more concentric
lattice-shells and six branched spines of equal size.
The genus _Hexacaryum_ is distinguished from the foregoing _Cubosphæra_ by
ramification of the six radial spines, and therefore exhibits the same
relation to it that _Hexancistra_ bears to _Hexastylus_, &c.
1. _Hexacaryum arborescens_, n. sp. (Pl. 23, figs. 4, 4_a_).
Shell composed of five, six, or more concentric shells, which are united by
six very large radial spines. The two medullary shells spherical, inner
with regular, circular, outer with irregular polygonal pores. All cortical
shells (third and following) not spherical, but regular octahedral, with
irregular polygonal meshes and thin bars. Radial spines prismatic, with
three wing-like, spirally twisted edges, which at equal distances send out
thin forked lateral branches (six on each {204}verticil); by further
ramification and communication of these branches the triangular net-plates
arise, filling out the sides of the octahedral cortical shells. Diameter of
all shells little different. The outer free parts of the six spines are
arborescent, twice to three times as long as the enclosed inner parts, and
bear six to eight verticils of free lateral branches, decreasing in size
towards the distal end (similar to _Arachnosphæra_).
_Dimensions._--Diameter of the six shells--(A) 0.015, (B) 0.04, (C) 0.1,
(D) 0.16, (E) 0.22, (F) &c.; average distance of the concentric octahedra =
0.06; length of the radial spines 0.3 to 0.4 and more, breadth 0.02.
_Habitat._--Central Pacific, Station 274, surface.
Subfamily HEXADORIDA,[118] Haeckel, 1881, Prodromus, pp. 449, 455.
_Definition._--#Cubosphærida# with spongy spherical or octahedral shell
(with or without enclosed concentrical lattice-shells).
Genus 85. _Cubaxonium_,[119] n. gen.
_Definition._--#Cubosphærida# with solid spongy spherical or octahedral
shell, without latticed medullary shell in the centre, and with six simple
radial spines of equal size.
The genus _Cubosphæra_ may be regarded as a form of _Styptosphæra_, which
develops six radial spines, opposite in pairs in the three dimensive axes.
The solid spongy framework of the shell assumes the outer form either of a
sphere, or of a regular octahedron.
1. _Cubaxonium spongiosum_, n. sp.
Spongy shell spherical, composed of a very dense spongy framework of nearly
uniform structure; the meshes three to four times as broad as the bars;
surface almost smooth. Six spines cylindrical, twice to three times as long
as the diameter of the spongy sphere, about as broad as one half mesh.
_Dimensions._--Diameter of the sphere 0.2, meshes 0.006 to 0.008, bars
0.002; length of the spines 0.4 to 0.5, breadth 0.004.
_Habitat._--South Pacific, Station 288, surface.
2. _Cubaxonium octahedrum_, n. sp.
Spongy shell octahedral, composed of a loose spongy framework of nearly
uniform structure; the meshes ten to twelve times as broad as the bars;
surface thorny. Six spines three-sided {205}pyramidal, longer than the
diameter of the octahedron, arising from its six corners, as broad at the
base as one mesh.
_Dimensions._--Diameter of the shell 0.15, meshes 0.01 to 0.012, bars
0.001; length of the spines 0.2, basal breadth 0.01.
_Habitat._--South Pacific, Station 300, surface.
Genus 86. _Hexadoras_,[120] Haeckel, 1881, Prodromus, p. 455.
_Definition._--#Cubosphærida# with spongy spherical shell and one simple
latticed medullary shell in its centre, having six simple spines of equal
size.
The genus _Hexadoras_ exhibits the same structure of the spongy shell as
_Spongoplegma_, but differs from it in the production of six dimensive
spines. In the centre lies one simple, latticed, medullary shell, which is
either spherical or octahedral. In the latter case the six spines arise
from the six corners of the octahedron.
1. _Hexadoras axophæna_, n. sp.
Medullary shell spherical, with regular hexagonal meshes, twice as broad as
the bars. Cortical shell entirely enclosing it, with loose irregular
framework and thorny surface. Diameter of the outer shell three times as
large as that of the inner. Six radial spines arising from the medullary
shell, four to five times as long as the radius of the cortical shell,
three-sided prismatic, with straight dentated edges.
_Dimensions._--Diameter of the outer shell 0.15, inner 0.05; length of the
spines 0.3 to 0.4.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
2. _Hexadoras lychnosphæra_, n. sp.
Medullary shell spherical, with regular, circular, hexagonally framed
pores, three times as broad as the bars. Cortical shell enveloping it, with
loose irregular framework and spiny surface. Diameter of the outer shell
eight times as large as that of the inner. Six radial spines arising from
the inner shell, three-sided prismatic, with dentated, spirally contorted
edges, seven times as long as the diameter of the medullary shell, with
three lateral branches at the distal end (similar to _Lychnosphæra_, Pl.
11, fig. 1).
_Dimensions._--Diameter of the outer shell 0.5, inner 0.06; total length of
the spines 0.4, breadth 0.01.
_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.
3. _Hexadoras octahedrum_, n. sp.
Medullary shell regular octahedral, with irregular polygonal meshes, five
times as broad as the bars. Cortical shell enveloping it, with dense spongy
framework, also octahedral with rough surface. {206}Diameter of the outer
shell five times as large as that of the inner. Six radial spines very
long, arising from the six corners of the inner and piercing the spongy
mass of the outer shell, considerably exceeding it at the free distal end,
three-sided prismatic, with elegantly denticulate edges.
_Dimensions._--Diameter of the outer shell 0.2, inner 0.04; total length of
the spines 0.3 or more, breadth 0.02.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
Genus 87. _Hexadoridium_,[121] Haeckel, 1881, Prodromus, p. 455.
_Definition_.--#Cubosphærida# with spongy spherical shell and two
concentric latticed medullary shells in its centre, having six simple
spines of equal size.
The genus _Hexadoridium_ differs from _Hexadoras_ in the duplication of the
medullary shell, and exhibits therefore the same relation to it that
_Spongodictyon_ bears to _Spongoplegma_. In the only known species the six
spines are opposite, arranged quite regularly in pairs in the three
dimensive axes, and consequently represent the three axes of a regular
crystal or cube.
1. _Hexadoridium streptacanthum_, n. sp. (Pl. 25, figs. 1, 1_a_).
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, five times as broad as the outer
medullary shell, regular octahedral. Six radial spines, arising from the
latter, are thinned at the inner end, three to five times as long as the
diameter of the cortical shell, and nearly as broad as the inner medullary
shell, with three dentated and spirally contorted edges. (Very similar to
the common _Spongosphæra streptacantha_, with irregular and variable number
and dispositions of spines; possibly its ancestral form?).
_Dimensions._--Diameter of the cortical shell 0.2, of the outer medullary
shell 0.04, inner 0.02; length of the spines 1 mm. and more, breadth 0.02.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
Family X. #ASTROSPHÆRIDA# (Pls. 11, 18-20, 26-30).
_Astrosphærida_, Haeckel, 1881, Prodromus, p. 449.
_Definition._--#Sphæroidea# with numerous (eight to twelve or more,
commonly between twenty and sixty) radial spines on the surface of the
spherical shell; living solitary (not associated in colonies).
The family #Astrosphærida#, the largest and most varied of all
#Sphæroidea#, is distinguished from the other members of this group by the
possession of numerous {207}radial spines, which are either regularly or
irregularly disposed on the surface of the spherical shell. The extreme
variability and richness of form in this family is mainly due to the
different size, shape, and disposition of these radial spines.
The simplest Astrosphærida are the Coscinommida, with a single spherical or
polyhedral lattice-shell. To this ancestral group all other subfamilies can
be opposed as "Astrosphærida composita," since their skeleton is composed
of two or more concentric lattice-shells: two in the Haliommida, three in
the Actinommida, four in the Cromyommida, five or more in the Caryommida.
In these four subfamilies the concentric shells are all simple (not spongy)
fenestrated spheres or endospherical polyhedra. In the sixth subfamily, the
Spongiommida, the shell is wholly or partially composed of spongy irregular
wicker-work, with or without a medullary shell in the centre.
_The Number of the Radial Spines_ in the Astrosphærida is extremely
variable, and ranges from eight to forty or more; in many cases more than
one hundred. Often each nodal-point of the network develops on the shell
surface one spine. Still more frequently the number of the spines is less
than that of the nodal-points. In all concentric Astrosphærida, having two
or more concentrical shells, we can distinguish "primary spines," as outer
prolongations of the inner radial beams connecting the shells, and
"secondary spines," developed only on the outer surface of the shell.
Naturally the former are of much greater importance than the latter. But we
can also often distinguish among the latter larger "main spines" and
smaller "by-spines," the latter commonly much more numerous than the
former.
_The Disposition of the Radial Spines_, either regular or irregular, is a
subject of great morphological interest, and remains to be exhausted by
further observations. The following cases of regular disposition have been
observed by me--(A) eight spines, opposite in pairs in four axes
corresponding to the four diagonal axes of a cube; (B) nine spines,
regularly disposed at equal distances (?) (not opposed in pairs); (C) ten
spines, disposed at equal distances (?); (D) twelve spines, regularly
disposed, corresponding to the twelve corners of the regular icosahedron;
(E) fourteen spines, quite regularly disposed (six corresponding to the
three axes of a regular octahedron, eight to the central points of its
eight faces); (F) sixteen spines, regularly disposed (?); (G) twenty spines
(very common!), either disposed in the same manner (after the law of
Johannes Müller) as in the ACANTHARIA (?), or corresponding to the twenty
corners of the regular or pentagonal dodecahedron, or disposed in the same
manner as in many #Larcoidea# (Tholonida, &c., to be described afterwards);
(H) twenty-four spines, regularly disposed (?); (I) thirty-two spines,
quite regularly disposed (twenty corresponding to the twenty corners of the
regular dodecahedron, twelve to the central points of its twelve faces);
(K) forty spines, nearly regularly (or quite symmetrically?) disposed. If
the number of the spines amounts to more than forty, it is as a rule
impossible to determine their regular disposition in a satisfactory manner.
{208}_Synopsis of the Genera of Astrosphærida._
-------------------------------------------------------------------------
I. Subfamily Coscinommida.
(One single latticed shell.)
-------------------------------------------------------------------------
{ All spines of the same
Spines all simple, not { kind, 88. _Acanthosphæra_.
branched and not {
tubulous. { Larger main spines and
{ smaller by-spines, 89. _Heliosphæra_.
Spines hollow conical tubes with porous walls, 90. _Conosphæra_.
Between simple spines the pores prolonged in hollow
tubes, 91. _Coscinomma_.
{ Spines with lateral
{ branches, 92. _Cladococcus_.
Spines branched or forked.{
{ Spines forked or
{ dichotomous, 93. _Elaphococcus_.
-------------------------------------------------------------------------
II. Subfamily Haliommida.
(Two concentric latticed shells.)
-------------------------------------------------------------------------
{ All spines equal,
{ simple, 94. _Haliomma_.
{
A. Elatommida, one { All spines simple, of
medullary and one cortical{ two different kinds, 95. _Heliosoma_.
shell. {
{ Spines branched, 96. _Elatomma_.
{ No by-spines, 97. _Leptosphæra_.
{
B. Diplosphærida, both { Inner by-spines, 98. _Diplosphæra_.
shells cortical. {
{ Outer by-spines, 99. _Drymosphæra_.
{
{ Outer and inner
{ by-spines, 100. _Astrosphæra_.
-------------------------------------------------------------------------
III. Subfamily Actinommida.
(Three concentric latticed shells.)
-------------------------------------------------------------------------
{ All spines equal, 101. _Actinomma_.
Radial spines not {
branched. { Larger main spines and
{ smaller by-spines, 102. _Echinomma_.
Radial spines branched or forked, 103. _Pityomma_.
-------------------------------------------------------------------------
IV. Subfamily Cromyommida.
(Three concentric latticed shells.)
-------------------------------------------------------------------------
{ All spines equal, 104. _Cromyomma_.
Radial spines not {
branched. { Larger main spines and
{ smaller by-spines, 105. _Cromyechinus_.
Radial spines branched or forked, 106. _Cromyodrymus_.
-------------------------------------------------------------------------
V. Subfamily Caryommida.
(Numerous, five to ten or more, concentric latticed shells.)
-------------------------------------------------------------------------
Two medullary shells and three or more cortical
shells (lattice work ordinary), 107. _Caryomma_.
{ Triangular meshes,
No medullary shells { simple bars, without
(lattice work { diagonal bars, 108. _Arachnopila_.
arachnoidal); three-sided {
prismatic spines, { Triangular meshes,
with verticils of three { simple bars; diagonal
forked branches. { bars between the 109. _Arachnopegma_.
(Arachnosphærida.) { shells,
{
{ Polygonal meshes, bars
{ branched, 110. _Arachnosphæra_.
-------------------------------------------------------------------------
VI. Subfamily Spongiommida.
(Spherical shell whole or partly spongy, with or without enclosed
latticed medullary shells in the centre.)
-------------------------------------------------------------------------
I. Tribe {Spongy {Spines simple, 111. _Spongiomma_.
Spongodrymida, { sphere {
without { solid. {Spines branched, 112. _Spongodrymus_.
latticed {
medullary {Spongy {Spines simple, 113. _Spongechinus_.
shell. { sphere {
{ hollow. {Spines branched, 114. _Spongothammus_.
{Framework arising
{ from the medullary
{ shell, 115. _Spongopila_.
{
{Medullary {Framework {No medullary by-spines,
II. Tribe { shell { separate { 116. _Rhizoplegma_.
Rhizoplegmida, { spherical. { from the {
with { { medullary {Medullary by-spines,
one single { { shell. { 117. _Lychnosphæra_.
latticed {
medullary {Medullary {Framework arising
shell. { shell a { immediately from
{ simple { the medullary
{ cube. { shell, 118. _Centrocubus_.
{ {
{ {Framework separate
{ { from the medullary
{ { shell, 119. _Octodendron_.
{Framework arising
III. Tribe Rhizosphærida, { from the medullary
with two concentric { shell, 120. _Spongosphæra_.
latticed medullary shells. {
{Framework separate
{ from the medullary
{ shell, 121. _Rhizosphæra_.
Subfamily COSCINOMMIDA, Haeckel.
_Heliosphærida_, Haeckel, 1881, Prodromus, pp. 449, 450.
_Definition._--#Astrosphærida# with one single spherical lattice-shell.
Genus 88. _Acanthosphæra_,[122] Ehrenberg, 1858, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 12.
_Definition._--#Astrosphærida# with one simple lattice-sphere, covered with
simple radial spines of the same kind.
The genus _Acanthosphæra_ exhibits the most simple form of all
_Astrosphærida_; a simple spherical lattice-shell, the surface of which is
covered by radial spines of one and the same kind. The number of the latter
is very variable, often twelve to twenty, regularly disposed; in other
cases forty to sixty or more; and sometimes at each nodal-point of the
network a spine is developed.
{210}Subgenus 1. _Rhaphidococcus_, Haeckel, 1862, Monogr. d. Radiol., p.
365 (_sensu emendato_).
_Definition._--Pores of the spherical shell regular or subregular, all of
nearly equal size and similar form. Radial spines arising from all the
nodal-points of the network.
1. _Acanthosphæra tenuissima_, Haeckel.
_Heliosphæra tenuissima_, Haeckel, 1862, Monogr. d. Radiol., p. 351, Taf.
ix. fig. 2.
Shell extremely thin walled, eight to ten times as broad as one pore.
Meshes or pores regular, hexagonal, with thread-like bars; five to seven on
the radius. At each nodal-point (between every three meshes) arises a
bristle-shaped radial spine, as long as the diameter of one pore.
_Dimensions._--Diameter of the shell 0.2 to 0.25, of the meshes or pores
0.025 to 0.03, bars below 0.0001; length of the spines 0.03.
_Habitat._--Mediterranean (Messina), North Atlantic (Canary Islands).
2. _Acanthosphæra tenuis_, n. sp.
Shell very thin walled, about twenty times as broad as one pore. Meshes
subregular, hexagonal, with thread-like bars; twelve to fourteen on the
radius. At each nodal-point arises a bristle-shaped radial spine, about as
long as the radius.
_Dimensions._--Diameter of the shell 0.3 to 0.35, pores 0.015 to 0.018,
bars below 0.001; length of the spines 0.12 to 0.16.
_Habitat._--Central Pacific, Stations 266 to 274, depth 2350 to 2925
fathoms.
3. _Acanthosphæra macropora_, n. sp.
Shell thin walled, five to six times as broad as one mesh. Pores regular,
circular, hexagonally framed, ten to twelve times as broad as the bars.
Radial spines bristle-shaped, as long as the diameter of one pore, arising
from all the nodal-points.
_Dimensions._--Diameter of the shell 0.07 to 0.08, pores 0.012, bars 0.001;
length of the spines 0.012.
_Habitat._--Central Pacific, Station 271, surface.
4. _Acanthosphæra micropora_, n. sp.
Shell thick walled, forty to fifty times as broad as one pore. Pores
regular, circular, hexagonally framed, half as broad as the bars. Radial
spines bristle-shaped, as long as the radius of the shell, arising from all
the nodal-points.
_Dimensions._--Diameter of the shell 0.22, pores 0.003, bars 0.006; length
of the spines 0.1.
_Habitat._--South Pacific, Station 288, surface.
{211}5. _Acanthosphæra dentata_, Haeckel.
_Cladococcus dentatus_, Haeckel, 1862, Monogr. d. Radiol., p. 367, Taf.
xiii. fig. 10.
Shell thin walled, eight to ten times as broad as one pore. Pores regular,
circular, hexagonally framed, three times as broad as the bars. Radial
spines arising from all the nodal-points of the network, three-sided
prismatic, with dentated or serrated edges, longer than the shell diameter.
_Dimensions._--Diameter of the shell 0.08, pores 0.01, bars 0.003; length
of the spines 0.1, breadth 0.003.
_Habitat._--Mediterranean (Messina), surface.
6. _Acanthosphæra acufera_, Haeckel.
_Rhaphidococcus acufer_, Haeckel, 1862, Monogr. d. Radiol., p. 366, Taf.
xiv. fig. 1.
_Cladococcus acufer_, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 800.
Shell thin walled, eight to ten times as broad as one mesh. Pores regular,
circular, three times as broad as the bars. Radial spines bristle-shaped,
arising with thicker conical bases from all the nodal-points, about as long
as the diameter of the shell.
_Dimensions._--Diameter of the shell 0.08, pores 0.01, bars 0.003; length
of the spines 0.08.
_Habitat._--Mediterranean (Messina); North Atlantic, Station 354, surface.
7. _Acanthosphæra castanea_, n. sp. (Pl. 26, fig. 3).
Shell thick walled, thirty times as broad as one mesh. Pores regular,
circular, nearly of the same breadth as the bars. Radial spines
bristle-shaped, arising with thicker conical bases from all the
nodal-points, scarcely half as long as the radius of the shell.
_Dimensions._--Diameter of the shell 0.15, pores and bars 0.005; length of
the spines 0.03.
_Habitat._--North Pacific, Station 244, surface.
8. _Acanthosphæra flosculenta_, n. sp.
Shell thick walled, thirteen times as broad as one mesh. Pores regular,
circular, three times as broad as the bars, with an elegant six-lobed frame
(Pl. 28, fig. 1_b_). In the intervals between the six lobes of each mesh
arise six conical radial spines (half as long as the radius), six around
each pore. (Differs from the similar _Haliomma flosculentum_, Pl. 28, fig.
1, in the absence of an enclosed medullary shell and the stronger
development of the spines.)
_Dimensions._--Diameter of the shell 0.13, pores 0.01, bars 0.003; length
of the spines 0.03.
_Habitat._--Indian Ocean, Cocos Islands, surface, Rabbe.
Subgenus 2. _Rhaphidocapsa_, Haeckel.
_Definition._--Pores of the spherical shell regular or subregular, all of
nearly equal size and similar form. Radial spines scattered at some
distance apart, not at all the nodal-points.
{212}9. _Acanthosphæra insignis_, Haeckel.
_Heliosphæra insignis_, R. Hertwig, 1879, Organismus der Radiol., p. 40,
Taf. v. fig. 7.
Shell thin walled, about ten times as broad as one mesh. Pores regular,
hexagonal, ten to twelve times as broad as the bars. Radial spines about
one hundred and twenty, arising from certain nodal-points of the network,
being as long as the diameter of the sphere, three-sided prismatic, with
three thin denticulated edges.
_Dimensions._--Diameter of the shell 0.2, pores 0.02, bars 0.002; length of
the spines 0.18, breadth 0.003.
_Habitat._--Cosmopolitan; Mediterranean (Messina), Atlantic (Stations 325,
347), Indian (Ceylon), Pacific (Stations 270 to 274), surface.
10. _Acanthosphæra fortispina_, n. sp.
Shell thin walled, about six times as broad as one mesh. Pores subregular,
hexagonal, with thread-like bars; three to four on the radius. Radial
spines about twenty, three-sided pyramidal, as long as the diameter, and
one-third as broad at the base as one pore.
_Dimensions._--Diameter of the shell 0.06 to 0.09, pores 0.01 to 0.014,
bars below 0.001; length of the spines 0.07 to 0.08, basal breadth 0.03 to
0.04.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
11. _Acanthosphæra mucronata_, n. sp. (Pl. 26, fig. 7).
Shell thick walled, fifteen times as broad as one pore. Pores regular,
circular, hexagonally framed, funnel-shaped, three times as broad as the
bars. Radial spines twenty to thirty, dagger-shaped or spindle-shaped,
angular, twice as broad in the middle as one pore, about as long as the
radius.
_Dimensions._--Diameter of the shell 0.11, pores 0.0075, bars 0.0025;
length of the spines 0.06, breadth 0.015.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
12. _Acanthosphæra clavata_, n. sp. (Pl. 26, fig. 8).
Shell thick walled, ten to twelve times as broad as one mesh. Pores
subregular, circular, three times as broad as the bars. Radial spines
twenty, club-shaped, angular, with prominent edges, twice as broad at the
distal end as one pore, about as long as the radius.
_Dimensions._--Diameter of the shell 0.11, pores 0.01, bars 0.003; length
of the spines 0.06, breadth 0.02.
_Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms.
13. _Acanthosphæra marginata_, n. sp.
Shell thick walled, twelve times as broad as one mesh. Pores regular,
circular double-edged, four times as broad as the bars. Radial spines
conical, fourteen in number, about as long as the {213}radius, and as broad
at the base as one mesh. Six spines correspond to the six corners of a
regular octahedron, eight to the centre of the eight faces.
_Dimensions._--Diameter of the shell 0.1, pores 0.008, bars 0.002; radial
spines 0.06, basal breadth 0.01.
_Habitat._--Central Pacific, Station 274, surface.
14. _Acanthosphæra florida_, n. sp.
Shell thick walled, fifteen times as broad as one mesh. Pores regular,
circular, hexagonally lobed, separated by prominent funnel-shaped crests of
half the breadth. Twenty conical radial spines, half as long as the radius,
as broad at the base as one funnel.
_Dimensions._--Diameter of the shell 0.15, pores 0.01, bars 0.005; length
of the spines 0.04, basal breadth 0.02.
_Habitat._--South Atlantic, Station 325, depth 2650 fathoms.
15. _Acanthosphæra enneacantha_, n. sp.
Shell thin walled, fourteen times as broad as one mesh. Pores regular,
circular, twice as broad as the bars. Nine radial spines, regularly
disposed, as long as the shell diameter, three-sided prismatic, with
pyramidal apex, as broad as one mesh.
_Dimensions._--Diameter of the shell 0.14, pores 0.01, bars 0.005; length
of the spines 0.15, breadth 0.01.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
16. _Acanthosphæra octahedralis_, n. sp.
Shell thick walled, octahedral, fourteen times as broad as one mesh. Pores
regular, circular, three times as broad as the bars. Fourteen radial
spines, regularly disposed, conical, as long as the radius of the shell,
twice as broad at the base as one mesh. Six spines correspond to the six
corners of a regular octahedron, eight to the central points of its eight
faces.