_Definition._--Shell with fifty-four sutures; four polar plates on each
pole of the main axis different in pairs; two major hexagonal meeting in a
polar suture (the "hydrotomical suture"); two minor pentagonal, not meeting
together (separated by that hydrotomical suture). Spherical shell therefore
composed of eight hexagonal plates (four equatorial and four polar) and by
twelve pentagonal plates (eight tropical and four polar plates).
4. _Dorataspis loricata_, Haeckel.
_Dorataspis loricata_, Haeckel, 1862, Monogr. d. Radiol., p. 415, Taf.
xxi. figs. 3-6.
Shell with fifty-four sutures and fifty-four sutural meshes, with eight
hexagonal and twelve pentagonal plates. Both aspinal meshes of each plate
kidney-shaped or roundish, nearly of the {815}same size as the sutural
meshes. Radial spines cylindrical; their outer half on the pointed distal
end two-edged and longer than the inner half.
_Dimensions._--Diameter of the shell 0.14, of its meshes 0.008 to 0.016.
_Habitat._--Mediterranean (Messina), North Atlantic (Canary Islands),
Azores, surface.
5. _Dorataspis typica_, n. sp. (Pl. 138, figs. 4, 4_a_).
Shell with fifty-four crest-like sutures and fifty-four circular sutural
meshes, with eight hexagonal and twelve pentagonal plates. Both aspinal
meshes of each plate elliptical, twice to three times as broad as the
sutural meshes. Aspinal meshes of the four equatorial plates twice as broad
as those of the sixteen other plates. The meshes are surrounded by elevated
and denticulated crests (incipient spine-sheaths). Radial spines
compressed, more or less two-edged; outer pointed half somewhat larger than
the inner half. (In this typical species the composition of the shell
prevailing in the majority of Ceriaspida is very clear.)
_Dimensions._--Diameter of the shell 0.15 to 0.18, of the aspinal pores
0.02 to 0.03, of the sutural pores 0.01.
_Habitat._--Central Pacific, Stations 270 to 274, surface and in various
depths.
6. _Dorataspis micropora_, n. sp. (Pl. 138, fig. 3).
Shell with fifty-four sutures and fifty-four very small sutural meshes,
with eight hexagonal and twelve pentagonal plates. Both aspinal meshes of
each plate elliptical, four to six times as broad as the sutural meshes.
Radial spines in the outer half conical, somewhat shorter than in the inner
cylindrical half.
_Dimensions._--Diameter of the shell 0.11, of the aspinal pores 0.01 to
0.02, of the sutural pores 0.003.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
7. _Dorataspis gladiata_, n. sp.
Shell with fifty-four sutures and one hundred to one hundred and twenty
sutural meshes, with eight hexagonal and twelve pentagonal plates. Both
aspinal meshes elliptical, three times as broad as the small sutural
meshes; commonly two meshes in each suture. Radial spines sword-shaped,
two-edged, tapering from the shell towards the two ends. (Resembles
_Belonaspis datura_, Pl. 139, fig. 9, but differs in the spherical shell,
the equal size of the four equatorial spines, and the absence of
by-spines.)
_Dimensions._--Diameter of the shell 0.12, of the aspinal pores 0.012, of
the sutural pores 0.004.
_Habitat._--Indian Ocean (Madagascar), Rabbe, surface.
8. _Dorataspis polypora_, n. sp.
Shell with fifty-four sutures and one hundred and sixty to two hundred
sutural meshes, with eight hexagonal and twelve pentagonal plates. Commonly
three meshes (sometimes four) on {816}each suture. Both aspinal meshes
kidney-shaped, four times as broad as the small sutural meshes. Radial
spines thick, in the inner longer part cylindrical, in the outer shorter
part conical. (Differs from all other species in the multiplication of the
sutural pores.)
_Dimensions._--Diameter of the shell 0.2, of the aspinal pores 0.016, of
the sutural pores 0.004.
_Habitat._--Equatorial Atlantic, Station 347, surface.
Genus 352. _Diporaspis_,[392] n. gen.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
forty aspinal pores (two pores in each plate). Surface of the shell without
combs and dimples, but armed with numerous by-spines.
The genus _Diporaspis_ has the same characteristic structure of the shell
as the typical _Dorataspis_, and differs from it only in the development of
numerous by-spines on the surface. The number of the sutures between the
twenty plates is sometimes fifty-two, at other times fifty-four, and in
each suture we find occasionally a single pore, at other times two or three
such pores.
Subgenus 1. _Diporasparium_.
_Definition._--Shell with fifty-two sutures, four polar plates on each pole
of the main axis meeting in one common point; therefore all eight polar
plates pentagonal and of equal size. Shell therefore composed of four
(equatorial) hexagonal plates, and of sixteen pentagonal (eight tropical
and eight polar) plates.
1. _Diporaspis nephropora_, n. sp. (Pl. 134, fig. 15).
Shell with fifty-two sutures and fifty-two sutural pores, with four
hexagonal and sixteen pentagonal plates. Both aspinal pores of each plate
kidney-shaped, about twice as broad as the circular sutural pores. Radial
spines thin, cylindrical, longer than the radius. By-spines forked, only
one-third as long as the radius.
_Dimensions._--Diameter of the shell 0.13, parmal pores 0.03, sutural pores
0.07.
_Habitat._--North Pacific, Station 244, surface.
2. _Diporaspis circopora_, n. sp.
Shell with fifty-two sutures and one hundred to one hundred and fifty
sutural pores, with four hexagonal and sixteen pentagonal plates. Both
aspinal pores of each plate circular, very large, six to eight times as
broad as the small circular sutural pores (in each suture two to three
pores). {817}Radial spines strongly compressed, two-edged; outer half
shorter than the inner. By-spines undulate, half as long as the radius.
_Dimensions._--Diameter of the shell 0.12, of the parmal pores 0.02 to
0.03, of the sutural pores 0.003 to 0.004.
_Habitat._--South Pacific, Station 287, surface.
Subgenus 2. _Diporaspidium_, Haeckel.
_Definition._--Shell with fifty-four sutures, four polar plates on each
pole of the main axis different in pairs: two major hexagonal meeting in a
polar ("geotomical") suture, two minor pentagonal, not meeting together
(separated by that suture). Shell therefore composed of eight hexagonal
plates (four equatorial and four polar) and of twelve hexagonal plates
(eight tropical and four polar).
3. _Diporaspis zygopora_, n. sp.
Shell with fifty-four sutures and fifty-four circular sutural pores: with
eight hexagonal and twelve pentagonal plates. Both aspinal pores of each
plate elliptical, three times as broad as the sutural pores. Radial spines
compressed, two-edged; outer half shorter than the inner. By-spines very
numerous, simple, one-third as long as the radius, forming coronels or
elegant circles around the pores (a small coronel around each sutural pore,
a large one around each couple of aspinal pores).
This typical species is nearly allied to _Dorataspis typica_ (Pl. 138, fig.
4), and may be derived from it by development of the coronels of by-spines.
_Dimensions._--Diameter of the shell 0.16, aspinal pores 0.03, sutural
pores 0.01.
_Habitat._--Central Pacific, Station 271, surface
Genus 353. _Orophaspis_,[393] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
forty aspinal pores (two pores in each plate). Surface of the shell without
combs, dimples, and by-spines. Each radial spine bears outside of the shell
two opposite free apophyses, which are either simple or branched.
The genus _Orophaspis_ differs not only from its ancestral form,
_Dorataspis_, but from all other Dorataspida in the development of peculiar
free apophyses on the radial spines, outside the shell. These apophyses,
two being opposite on each spine, appear as a repetition of the primary
apophyses of _Phractaspis_; they are either simple or branched, and
sometimes the branches are united together, forming an outer free shield
with two or four pores. These outer plates represent the beginning of a
second outer shell and form the transition to _Phractopelta_, the ancestral
form of the Phractopeltida.
{818}Subgenus 1. _Orophasparium_, Haeckel.
_Definition._--Free apophyses of the radial spines simple, not branched.
1. _Orophaspis astrolonche_, n. sp.
Parmal pores of the shell circular, twice as large as the sutural pores and
as the breadth of the bars. Radial spines very long, three to six times as
long as the diameter of the shell, compressed, two-edged; each with two
simple, opposite, triangular apophyses; their distance from the shell equal
to its diameter.
_Dimensions._--Diameter of the shell 0.05, parmal pores 0.004, sutural
pores 0.002.
_Habitat._--North Pacific, Station 239, surface.
2. _Orophaspis gladiata_, n. sp.
Parmal pores of the shell circular, of the same size as the sutural pores
and the bars. Radial spines thick, spindle-shaped, scarcely longer than the
diameter of the shell, each with two simple opposite conical apophyses;
their distance from the shell about equal to its radius.
_Dimensions._--Diameter of the shell 0.06, pores 0.003.
_Habitat._--Central Pacific, Station 265, surface.
Subgenus 2. _Orophaspidium_, Haeckel.
_Definition._--Free apophyses of the radial spines branched, their branches
free (not anastomosing).
3. _Orophaspis furcata_, n. sp. (Pl. 133, fig. 6).
Parmal pores of the shell roundish or elliptical, three times as broad as
the sutural pores and the bars. Radial spines very long, compressed, each
with two opposite apophyses, which are simply forked; their distance from
the shell somewhat greater than its diameter.
_Dimensions._--Diameter of the shell 0.06 to 0.08, parmal pores 0.006,
sutural pores 0.002.
_Habitat._--Central Pacific, Station 274, surface.
4. _Orophaspis ramosa_, n. sp.
Parmal pores of the shell circular, of the same size as the sutural pores
and the bars. Radial spines compressed, very long, each with two opposite
apophyses, which are more or less irregularly branched (commonly between
eight and twelve thin branches on each spine); their distance from the
shell smaller than its diameter.
_Dimensions._--Diameter of the shell 0.08, pores 0.006.
_Habitat._--North-West Pacific, Station 235, surface.
{819}Subgenus 3. _Stegaspis_, Haeckel, 1881, Prodromus, p. 468.
_Definition._--Free apophyses of the radial spines branched, and by reunion
of their anastomosing branches forming perforated shields.
5. _Orophaspis diporaspis_, n. sp.
Parmal pores of the shell circular, of the same size as the sutural pores
and the bars. Radial spines sword-shaped, two-edged, very broad; each spine
bears an elliptical free shield with two longish pores (opposite on the two
flat sides of the sword). Distance of the twenty free two-pored shields
from the shell about equal to its diameter.
_Dimensions._--Diameter of the shell 0.04, of the pores 0.004.
_Habitat._--South Pacific, Station 295, surface.
6. _Orophaspis tessaraspis_, n. sp.
Parmal pores of the shell roundish, somewhat larger than the sutural pores
and the bars. Radial spines very long, compressed; each spine bears a
roundish free shield with four irregular pores disposed in a cruciform
manner, the two larger pores being opposite on the flat sides of the spine,
the two smaller being opposite but on its two edges. Distance of the twenty
free four-pored shields from the shell about equal to its radius.
_Dimensions._--Diameter of the shell 0.05, of the pores 0.003.
_Habitat._--North Pacific, Station 239, surface.
Genus 354. _Ceriaspis_,[394] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
forty aspinal pores (two pores in each plate). Surface of the shell with
numerous dimples, separated by a network of elevated combs. No by-spines.
The genus _Ceriaspis_ has the same structure of the shell, as its ancestral
form _Dorataspis_, differing from it only in the development of high combs
or crests, which form on the surface of the shell a peculiar elevated
network. The dimples or funnel-shaped pits between these combs are either
all or partly perforated by the pores of the shell. Both the aspinal pores
of each plate are usually placed in one common dimple, whilst each sutural
pore is placed in its peculiar smaller dimple.
Subgenus 1. _Ceriasparium_, Haeckel.
_Definition._--Shell-surface with seventy to one hundred or more small
funnel-shaped dimples, each of which opens on the bottom by one pore or by
a couple of {820}apertures; twenty larger dimples in the centre of the
plates (each with a couple of aspinal pores) and fifty to one hundred or
more smaller dimples, each of which contains one sutural pore. No blind
dimples between the perforated dimples.
1. _Ceriaspis lacunosa_, n. sp.
Shell spherical with seventy-two funnel-shaped dimples, each of which is
perforated on the bottom by one or two apertures; twenty larger dimples in
the centre of the plates, each with two elliptical aspinal pores, and
fifty-two smaller sutural dimples between them, each with one circular pore
of half the size. No blind dimples. Radial spines quadrangular, stout;
their outer part shorter than the inner.
_Dimensions._--Diameter of the shell 0.1, of the forty parmal pores 0.01,
of the fifty-two sutural pores 0.005.
_Habitat._--South Atlantic, Station 330, surface.
2. _Ceriaspis scrobiculata_, n. sp.
Shell spherical, with seventy-four funnel-shaped dimples, each of which is
perforated on the bottom by one or two apertures; twenty larger dimples in
the centre of the plates, each with two kidney-shaped large pores, and
fifty-four smaller dimples on the sutures, each with one circular pore of
one-fourth of the size of the reniform pores. No blind dimples. Radial
spines cylindrical, the outer part longer than the inner.
_Dimensions._--Diameter of the shell 0.12, of the forty parmal pores 0.016,
of the fifty-four sutural pores 0.004.
_Habitat._--Central Pacific, Station 270, surface.
Subgenus 2. _Ceriaspidium_, Haeckel.
_Definition._--Shell-surface with funnel-shaped dimples (commonly one
hundred and seventy-six or one hundred and eighty-two), which on the bottom
are partly closed, partly perforated by one aperture (or by a pair of
pores). The blind dimples are placed on the corners of the twenty plates,
and are therefore either one hundred and four or one hundred and eight; if
there be no polar suture, the blind dimples are one hundred and four
(twenty-four on the four hexagonal equatorial plates, forty on the eight
pentagonal tropical plates, and forty on the eight pentagonal polar
plates); if, however, there be a polar suture on both main poles, the
number of blind dimples is one hundred and eight (twenty-four on the four
hexagonal equatorial and twenty-four on the four hexagonal polar plates,
two opposite on each pole; forty on the eight pentagonal tropical plates
and twenty on the four pentagonal polar plates, two opposite on each pole).
Between the blind dimples there are usually seventy-two to seventy-four
perforated {821}dimples, twenty larger parmal dimples (enclosing a radial
spine and a couple of aspinal pores) and fifty-two to fifty-four sutural
dimples (sometimes one hundred or more), each of which encloses one
sutural pore.
3. _Ceriaspis inermis_, n. sp. (Pl. 138, fig. 5).
Shell spherical, with one hundred and seventy-six funnel-shaped dimples,
one hundred and four of which are blind and seventy-two perforated; of the
latter, each of the fifty-two smaller contains a single sutural pore, each
of the twenty larger a couple of aspinal pores. The elliptical or
kidney-shaped aspinal pores are about twice as broad as the circular
sutural pores. Radial spines thin, compressed, two-edged; their outer
prolongation very short, rudimentary, scarcely higher than the axis of the
surrounding funnel, and projecting but slightly from its aperture.
_Dimensions._--Diameter of the shell 0.15, of the forty parmal pores 0.016,
of the fifty-two sutural pores 0.008.
_Habitat._--South Pacific, Station 289, surface.
4. _Ceriaspis favosa_, n. sp. (Pl. 138, fig. 6).
Shell polyhedral (icosahedral), with one hundred and eighty-two
funnel-shaped dimples, one hundred and eight of which are blind and
seventy-four perforated; of the latter, each of the fifty-four smaller
contains a single sutural pore, each of the twenty larger a couple of
aspinal pores. All pores roundish, nearly of the same size. Radial spines
thin, compressed, two-edged; their outer part somewhat longer than the
inner.
_Dimensions._--Diameter of the shell 0.12 to 0.13, of the pores 0.01 to
0.015.
_Habitat._--Central Pacific, Station 274, surface.
5. _Ceriaspis icosahedra_, n. sp.
Shell polyhedral (icosahedral), with one hundred and eighty-two
funnel-shaped dimples, one hundred and eight of which are blind and
seventy-four perforated; of the latter, each of the fifty-four smaller
contains one small sutural pore, each of the twenty larger a couple of
aspinal pores. The kidney-shaped aspinal pores are very large, four to six
times as broad as the small circular sutural pores. Radial spines strong,
quadrangular, their outer part from two to three times as long as the inner
part.
_Dimensions._--Diameter of the shell 0.16, of the parmal pores 0.015 to
0.02, of the sutural pores 0.003 to 0.004.
_Habitat._--Tropical Atlantic, Station 349, surface.
6. _Ceriaspis cicatricosa_, n. sp.
Shell spherical, with two hundred and fifty to three hundred (or more)
small funnel-shaped dimples, the majority of which are blind, the minority
perforated by pores; of the latter forty {822}are aspinal pores (two at the
base of each spine), the others sutural pores. All pores nearly of the same
size. As the shell of this species is very dark and thick-walled, it was
impossible to obtain more information with regard to the pores. Radial
spines very stout; the outer conical part shorter than the inner
cylindrical part.
_Dimensions._--Diameter of the shell 0.2, of the pores 0.006 to 0.008.
_Habitat._--North Pacific, Station 236, surface.
Genus 355. _Hystrichaspis_,[395] n. gen.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
forty aspinal pores (two pores in each plate). Surface of the shell with
numerous dimples, separated by a network of elevated combs. Numerous
by-spines.
The genus _Hystrichaspis_ has the same structure with regard to the shell,
as its ancestral form _Ceriaspis_, and differs from the latter only in
possessing numerous by-spines. Moreover, in the former the dimples of the
shell-surface are either all perforated by pores, or some of them are
blind.
Subgenus 1. _Hystrichasparium_, Haeckel.
_Definition._--Shell with seventy to one hundred or more funnel-shaped
dimples, each of which opens on the bottom by one aperture or by a couple
of pores; twenty larger dimples in the centre of the plates (each with a
couple of pores, sometimes also three couples) and fifty to one hundred or
more smaller dimples, each of which contains one sutural pore. No blind
dimples between the perforated dimples.
1. _Hystrichaspis pectinata_, n. sp. (Pl. 138, fig. 8).
Shell with numerous (one hundred to two hundred?) funnel-shaped dimples,
each of which is pierced at the bottom by one or two pores; twenty larger
dimples in the centre of the plates (each with two aspinal pores), and
fifty to one hundred and fifty or more smaller dimples (each with one
sutural pore). No blind dimples. Crests between the dimples armed with a
continuous series of simple by-spines. Radial main spines stout, in the
inner half cylindrical, in the outer conical, more or less compressed.
_Dimensions._--Diameter of the shell 0.13, of the pores 0.004 to 0.006.
_Habitat._--Tropical Atlantic, Station 352, surface.
2. _Hystrichaspis furcata_, n. sp. (Pl. 138, fig. 9).
Shell with numerous (one hundred to two hundred?) funnel-shaped dimples,
each of which is pierced at the bottom by one or two pores; twenty larger
dimples in the centre of the plates (each {823}with two large aspinal
pores), and fifty to one hundred and fifty or more smaller dimples (each
with one small sutural pore). No blind dimples. Crests between the
dimples armed with forked by-spines. Radial main spines stout, leaf-shaped,
tapering towards both ends.
_Dimensions._--Diameter of the shell 0.12, parmal pores 0.01, sutural pores
0.005.
_Habitat._--Central Pacific, Station 276, surface.
3. _Hystrichaspis cristata_, n. sp. (Pl. 138, fig. 11).
_Siphonasphis cristata_, Haeckel, 1882, Manuscript.
Shell with numerous (one hundred to two hundred?) funnel-shaped dimples,
each of which is pierced at the bottom by one or more pores. Twenty larger
dimples in the centre of the plates are pierced by the radial main-spines;
among these fourteen contain each a couple of aspinal pores; six others are
much larger, and contain each six larger pores; these six plates are two
opposite equatorial plates and four polar plates, placed in the same
meridian plane (the "hydrotomical plane"); in each of these six
"hydrotomical dimples" two pores are placed opposite to one another on the
two edges of the leaf-shaped spine, four others being opposite in pairs on
both flat sides of it. By this peculiar structure this species connects the
true _Hystrichaspis_ with _Hexalaspis_ and _Diploconus_; however the twenty
spines are of equal length, and the shell continues to be spherical. The
twenty radial main-spines are leaf-like and compressed. The crests between
the dimples are dentated by a series of small by-spines.
_Dimensions._--Diameter of the shell 0.15, of the aspinal pores 0.01, of
the sutural pores 0.005.
_Habitat._--North Pacific, Station 240, surface.
Subgenus 2. _Hystrichaspidium_, Haeckel.
_Definition._--Shell-surface with numerous funnel-shaped dimples (commonly
one hundred and seventy-six to one hundred and eighty-two), which on the
bottom are partly closed, partly perforated by one aperture (or by a pair
of pores). The blind dimples are situated on the corners of the twenty
plates; their number is commonly one hundred and four or one hundred and
eight, sometimes more. The perforated dimples, alternating with the former,
are usually seventy-two to seventy-four, sometimes more; twenty larger
parmal dimples (each with a couple of aspinal pores, sometimes also with
three such couples) and fifty-two to fifty-four sutural dimples, sometimes
one hundred or more (each with one sutural pore). (Compare the definition
of _Ceriaspidium_, p. 820.)
4. _Hystrichaspis dorsata_, n. sp. (Pl. 138, fig. 10).
Shell with one hundred and seventy-six funnel-shaped dimples, one hundred
and four of which are blind and seventy-two perforated; of the latter, each
of the fifty-two smaller contains a single {824}sutural pore, each of the
twenty larger a couple of aspinal pores; the elliptical aspinal pores are
twice as broad as the circular sutural pores. The crests between the
dimples are armed with simple scattered short by-spines; usually in the
nodal points, where three combs meet, there exist three or two divergent
by-spines. The twenty radial main-spines are thin and long, compressed.
_Dimensions._--Diameter of the shell 0.22, of the aspinal pores 0.02, of
the sutural pores 0.01.
_Habitat._--Central Pacific, Station 271, surface.
5. _Hystrichaspis armata_, n. sp.
Shell with one hundred and seventy-six funnel-shaped dimples, one hundred
and four of which are blind and seventy-two perforated; of the latter, each
of the fifty-two smaller contains a single sutural pore, each of the twenty
larger a couple of aspinal pores. Crests between the dimples comb-like,
armed with a series of simple by-spines. Twenty main-spines very stout, in
the inner part cylindrical, in the outer shorter part conical.
_Dimensions._--Diameter of the shell 0.25, of the aspinal pores 0.02, of
the sutural pores 0.01.
_Habitat._--South-East Pacific, Station 300, surface.
6. _Hystrichaspis sulcata_, n. sp.
Shell with one hundred and eighty-two funnel-shaped dimples, one hundred
and eight of which are blind and seventy-four perforated; of the latter,
each of the fifty-four smaller contains a single sutural pore, each of the
twenty larger a couple of aspinal pores. All pores nearly of the same size,
very small. Crests between the dimples very high, sulcated, on the free
edge serrate with short very numerous, simple by-spines. Radial main-spines
very stout and short, conical.
_Dimensions._--Diameter of the shell 0.2, of the pores 0.003.
_Habitat._--South Atlantic, Station 325, surface.
7. _Hystrichaspis foveolata_, n. sp.
Shell with very numerous (three hundred to four hundred?) small and deep
funnel-shaped dimples, the majority of which are blind, the minority
perforated; among the latter there are forty larger aspinal pores; the
other smaller (scarcely half as large) pores are sutural. Crests between
the dimples densely armed with simple short by-spines. Radial main-spines
stout, leaf-shaped.
_Dimensions._--Diameter of the shell 0.12, of the aspinal pores 0.01, of
the sutural pores 0.004.
_Habitat._--Tropical Atlantic, Station 338, surface.
8. _Hystrichaspis divaricata_, n. sp.
Shell with numerous (two hundred to three hundred?) funnel-shaped dimples,
the majority of which are blind, the minority perforated; among the latter
there are forty larger aspinal pores. {825}Crests between the dimples armed
with long forked by-spines with divergent fork-branches. Radial spines
cylindrical, very long and thick, longer than the diameter of the shell.
_Dimensions._--Diameter of the shell 0.14, aspinal pores 0.08, sutural
pores 0.03.
_Habitat._--Central Pacific, Station 266, surface.
9. _Hystrichaspis fruticata_, n. sp. (Pl. 138, fig, 7).
Shell with numerous (one hundred and fifty to two hundred?) funnel-shaped
dimples, the majority of which are blind, the minority perforated; forty
aspinal pores elliptical, of the same size as the circular sutural pores.
Crests between the dimples bearing elegant arborescent by-spines. Twenty
radial main-spines long and thin, cylindrical or a little compressed.
_Dimensions._--Diameter of the shell 0.17, pores 0.01.
_Habitat._--Tropical Pacific, Station 275, surface.
10. _Hystrichaspis serrata_, n. sp.
Shell with numerous (two hundred to three hundred?) funnel-shaped dimples,
the majority of which are blind, the minority perforated; forty aspinal
pores of the same size as the sutural pores. Crests between the dimples
covered with denticulated by-spines. Twenty radial main-spines compressed,
two-edged, with serrated edges, about as long as the diameter of the shell.
_Dimensions._--Diameter of the shell 0.21, pores 0.012.
_Habitat._--North Pacific, Station 238, surface.
Genus 356. _Coscinaspis_,[396] n. gen.
_Definition._--#Doratispida# with twenty plates, which are perforated by
eighty to two hundred or more parmal pores (two aspinal and two to ten or
more coronal pores in each plate). Surface without by-spines.
The genus _Coscinaspis_, together with the following nearly allied genus
_Acontaspis_, may be separated from the other Ceriaspida as a peculiar
tribe, _Coscinaspida_. This tribe is characterised by the larger number of
the parmal pores. Whilst in all other Ceriaspida this number is constantly
forty (only two pores in each plate), here it may be from eighty to two
hundred or more; in each shield the two primary "aspinal pores" are
surrounded by a circle of two to ten or more (commonly eight to twelve)
"coronal pores." The number of sutural pores in this group is also usually
larger.
{826}Subgenus 1. _Coscinasparium_, Haeckel.
_Definition._--Plates of the shell smooth, without crests, not dimply.
1. _Coscinaspis peripora_, n. sp. (Pl. 138, fig. 1).
Shell thin walled, with smooth surface, without crests and dimples,
perforated by pores of very different sizes. Forty aspinal pores, roundish
or elliptical, of about the same size as the fifty or sixty violin-shaped
sutural pores, and three to four times as broad as the small roundish
coronal pores, which are irregularly formed and distributed, four to eight
occurring on each plate (altogether one hundred to one hundred and twenty).
Radial spines roundish, somewhat compressed; inner and outer half nearly of
the same length.
_Dimensions._--Diameter of the shell 0.12, aspinal pores 0.01 to 0.012,
coronal pores 0.003.
_Habitat._--North-West Pacific, Station 235, surface.
2. _Coscinaspis stigmopora_, n. sp.
Shell very thin walled, with smooth surface, without crests and dimples,
perforated by pores of very different sizes. Forty aspinal pores, roundish,
of about the same size as the fifty or sixty violin-shaped sutural pores,
their diameter being about one-fifth of that of the plates. Coronal pores
very numerous (two hundred to four hundred) and very small, irregularly
scattered, ten to twenty occurring in each plate. Sutures strongly
denticulated. Radial spines very thin and short, cylindrical.
_Dimensions._--Diameter of the shell 0.12 to 0.15, aspinal and sutural
pores 0.01, coronal pores 0.001 to 0.003.
_Habitat._--North Pacific, Station 257, surface.
3. _Coscinaspis rhacopora_, n. sp.
Shell very thin walled, with smooth surface, without crests and dimples,
perforated by very irregular pores of very different sizes and forms;
commonly more or less lobed or sinuate. Forty aspinal pores and fifty to
eighty sutural pores, larger than the numerous (one hundred to two hundred)
irregularly scattered coronal pores. Sutures very sinuate. Radial spines
cylindrical, thin and long.
_Dimensions._--Diameter of the shell 0.15 to 0.18, aspinal and sutural
pores 0.01 to 0.02, coronal pores 0.001 to 0.005.
_Habitat._--Central Pacific, Station 274.
4. _Coscinaspis coscinopora_, n. sp.
Shell thin walled, with smooth surface, without crests and dimples,
perforated by very numerous pores of circular form, but of different sizes.
Forty aspinal pores and one hundred to two hundred {827}sutural pores much
larger than the coronal pores, which are very small and very numerous
(fifty to sixty on each plate). Sutures sinuate. Radial spines compressed,
outer and inner half nearly of equal length.
_Dimensions._--Diameter of the shell 0.3, aspinal and sutural pores 0.01 to
0.015, coronal pores 0.001 to 0.002.
_Habitat._--Tropical Atlantic, Station 338, surface.
5. _Coscinaspsis polypora_, n. sp. (Pl. 136, fig. 8).
Shell very thin walled, with smooth surface, without crests and dimples,
the two aspinal pores of each plate narrow, lanceolate, ten to twelve times
as long as broad and half as long as the radius of each plate. Coronal
pores irregular, polygonal, very numerous (two hundred to three hundred on
each plate), commonly arranged more or less regularly in ten to twelve
series parallel to the longitudinal diameter of the aspinal spines (ten to
twenty pores in each series). Sutural pores irregular, polygonal, very
numerous. Radial spines very thin and long, cylindrical.
_Dimensions._--Diameter of the shell 0.24; length of the aspinal pores
0.04, breadth 0.004; coronal and sutural pores 0.002 to 0.01.
_Habitat._--Tropical Atlantic, Station 349, surface.
6. _Coscinaspis orthopora_, n. sp.
Shell very thin walled, with smooth surface, without crest and dimples. All
pores of nearly equal size and form; quadrangular, mostly rectangular; one
hundred to two hundred, separated by two systems of parallel bars,
perpendicular one to another, occur in each plate. Sutural pores mostly
triangular. Radial spines very thin and long, cylindrical, somewhat
compressed. (Similar to those of _Phatnaspis lacunaria_, Pl. 136, fig. 9,
but spherical, not ellipsoidal.)
_Dimensions._--Diameter of the shell 0.2, pores 0.008 to 0.012.
_Habitat._--Central Pacific, Station 272, surface.
7. _Coscinaspis parmipora_, n. sp. (Pl. 137, fig. 9).
_Craniaspis parmipora_, Haeckel, 1866, Manuscript.
_Dorataspis parmipora_, Haeckel, 1881, Prodromus, Atlas.
Shell thin walled, with smooth surface, without crests and dimples. There
are no sutural pores, since all twenty plates are connected by perfect
sinuate sutures (therefore this excellent species may perhaps better
represent a peculiar genus, called by me in 1866 _Craniaspis_). All pores
are parmal pores; each plate with two elliptical aspinal pores, which are
twice to five times broader than the numerous, roundish irregularly
scattered coronal pores (thirty to fifty occurring on each plate). The
radial spines are quite internal, that is, not prolonged on the outside of
the shell; in this respect they resemble those of _Sphærocapsa_.
_Dimensions._--Diameter of the shell 0.16, aspinal pores 0.01, coronal
pores 0.002 to 0.005.
_Habitat._--North Atlantic, Canary Islands (Lanzerote), surface.
{828}8. _Coscinaspis isopora_, n. sp. (Pl. 134, figs. 13, 14).
Shell thick walled, with smooth surface, without crests and dimples. All
pores of the shell nearly of the same size and of similar form, about as
broad as the bars between them, and about two hundred in number, viz.,
fifty to sixty (regularly fifty-two or fifty-four) sutural pores and one
hundred and forty to one hundred and fifty parmal pores (forty aspinal
kidney-shaped pores, and one hundred to one hundred and ten coronal
circular pores: six in the angles of each equatorial plate, and five in the
angles of each tropical and polar plate; if the disposition be quite
regular, one hundred and four or one hundred and eight). Radial spines
short, rudimentary, conical.
_Dimensions._--Diameter of the shell 0.2, of the pores and bars 0.012.
_Habitat._--Tropical Pacific, Station 218 (off New Guinea), surface.
Subgenus 2. _Coscinaspidium_, Haeckel.
_Definition._--Surface of the shell dimply, with a network of prominent
crests.
9. _Coscinaspis ceriopora_, n. sp.
Shell thick-walled, with numerous (one hundred and sixty to two hundred?)
funnel-shaped dimples, which are separated by prominent crests; on the
bottom of each dimple there is a simple or double circular pore. If this
species be quite regularly developed, it closely resembles the preceding,
differing from it mainly in the prominent combs of the surface. It
resembles also _Ceriaspis favosa_, Pl. 138, fig. 6; but whilst in this
latter the majority of the dimples are blind, here they are all perforated.
The twenty aspinal dimples (in the centre of each plate) present at the
bottom a couple of pores, all other dimples a single pore. Among the latter
there are fifty to sixty sutural pores and one hundred to one hundred and
ten coronal pores, viz., six in each equatorial plate, and five in each of
the other plates; but the number is not quite constant. Radial spines
strong, in the inner part cylindrical, in the outer conical.
_Dimensions._--Diameter of the shell 0.15, of the pores and bars 0.01.
_Habitat._--Tropical Pacific, Station 215, surface.
Genus 357. _Acontaspis_,[397] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
eighty to two hundred or more parmal pores (in each plate two aspinal and
two to ten or more coronal pores). Surface covered with by-spines.
The genus _Acontaspis_ has the same characteristic structure of the shell
as _Ceriaspis_, differing from it only in the presence of numerous
by-spines. Each plate is perforated by four to sixteen or more (commonly
ten to twelve) parmal pores, the two central of which are primary "aspinal
pores," all the others being secondary "coronal pores."
{829}Subgenus 1. _Acontasparium_, Haeckel.
_Definition._--Plates of the shell not dimply, without prominent crests.
1. _Acontaspis lanceolata_, n. sp.
Shell thin walled, even, without crests and dimples between them,
perforated by about three hundred pores of different sizes: forty aspinal
pores elliptical, about as large as the irregular (fifty to sixty) sutural
pores, and two to four times as broad as the small circular coronal pores
(eight to twelve being on each plate, altogether about two hundred).
Between the pores numerous short conical by-spines. Radial main spines
lanceolate, about as long as the radius. (Similar to _Coscinaspis
peripora_, Pl. 138, fig. 1, but with broad lanceolate spines and numerous
short by-spines.)
_Dimensions._--Diameter of the shell 0.15, aspinal and sutural pores 0.012
to 0.015, coronal pores 0.004 to 0.008.
_Habitat._--South Atlantic, Station 325, surface.
Subgenus 2. _Acontaspidium_, Haeckel.
_Definition._--Surface of the shell dimply, with a network of prominent
crests.
2. _Acontaspis hastata_, n. sp. (Pl. 134, fig. 16).
Shell thick walled, with numerous (one hundred and seventy to one hundred
and ninety) dimples, which are separated by an elevated network of
prominent crests. In the centre of each plate a larger dimple with a couple
of aspinal pores, surrounded by a corona of ten or twelve smaller dimples,
each of which contains a single pore (a coronal and sutural alternately).
All pores circular or roundish, nearly of the same size. If the shell be
quite regularly developed, there are fifty to sixty sutural pores and one
hundred to one hundred and ten coronal pores (six in each equatorial plate,
five in each of the other plates). The knobs of the meeting crests are
conical, and bear each a simple short by-spine. Radial main spines
compressed, at the distal end spear-shaped, with a rhomboidal plate below
the apex, about as long as the radius.
_Dimensions._--Diameter of the shell 0.18, of the pores and bars 0.01.
_Habitat._--Western Tropical Pacific (off the Philippines), Station 215.
3. _Acontaspis furcata_, n. sp.
Shell thick walled, dimply, with a network of crests, of the same
composition as in the foregoing species, with one hundred and seventy to
one hundred and ninety dimples (twenty aspinal, one hundred to one hundred
and ten coronal and fifty to sixty sutural dimples). All dimples and pores
nearly of the same size. Each node of the crested network bears a stout
by-spine, which is forked {830}on the base, with two divergent straight
branches (similar to those of _Hystrichaspis furcata_, Pl. 138, fig. 9).
Radial main spines two-edged, sword-like, nearly as long as the diameter of
the shell.
_Dimensions._--Diameter of the shell 0.13, of the pores 0.008.
_Habitat._--Central Pacific, Station 272, surface.
4. _Acontaspis capillata_, n. sp.
Shell very dark and thick walled, non-transparent, with very numerous
(three hundred to four hundred or more?) deep funnel-shaped dimples, each
of which is perforated by a small circular pore (forty aspinal, two hundred
to three hundred coronal, and fifty to one hundred sutural pores?). The
high crests between the dimples bear very numerous simple by-spines, nearly
half as long as the radius, so that the shell appears covered with hairs.
Radial main spines very long and thin, cylindrical, longer than the
diameter of the shell.
_Dimensions._--Diameter of the shell 0.2, of the pores 0.012.
_Habitat._--North Pacific, Station 244, surface.
Subfamily 2. TESSARASPIDA, Haeckel.
_Definition._--#Dorataspida# with twenty radial spines, each of which bears
four crossed apophyses (opposite in pairs). The spherical shell is composed
either of the meeting branches of these apophyses (Stauraspida), or of
twenty perforated plates, produced by concrescence of their branches
(Lychnaspida).
A. Tribe II. #Stauraspida#, Haeckel, 1881, Prodromus, p. 467.
_Definition._--#Dorataspida# with spherical shell, which is composed either
of the meeting branches of the four crossed apophyses only, or exhibits
four to twelve perforated plates which are produced by the crossed
apophyses of four to twelve radial spines (but never of all twenty spines).
Each plate bears four crossed pores.
Genus 358. _Stauraspis_,[398] Haeckel, 1881, Prodromus, p. 467.
_Definition._--#Dorataspida# without perforated plates; shell composed only
of the meeting branches of the four crossed apophyses, which arise
(opposite in pairs) from each radial spine. Condyles of the branch-ends
without by-spines.
The genus _Stauraspis_ is the most simple and primitive form among all
Tessaraspida, or that subfamily of Dorataspida, in which the shell is
composed of twenty {831}radial spines, each of which bears four crossed
apophyses. The subfamily may be divided into two different tribes, the
Stauraspida and Lychnaspida. In the Stauraspida either all twenty spines,
or a part of them, bear no perforated plates, and the shell is composed
wholly or partially of the meeting branches of their apophyses. In the
Lychnaspida, however, the four apophyses of each single spine form, by
reunion of their recurved branches, a plate or shield with four crossed
aspinal pores. The Lychnaspida represent therefore a more developed stage
in the shell-formation than the simpler Stauraspida. _Stauraspis_, as the
common ancestral form of both, may be derived phylogenetically from
_Xiphacantha_ or _Stauracantha_, which differ only by the apophyses or
branches of the apophyses not meeting. These branches (originally eight on
each spine) are either simple or again branched.
Subgenus 1. _Staurasparium_, Haeckel.
_Definition._--Apophyses of the spines simple, not branched; therefore each
spine with four sutural condyles.
1. _Stauraspis cruciata_, n. sp. (Pl. 134, fig. 5).
Radial spines thin, quadrangular, prismatic; outer and inner half nearly of
equal length. Central bases pyramidal, with wing-like edges. Four apophyses
of each spine simple, not branched, with thin condyles. Large meshes of the
shell ten to twenty times as broad as the bars. This and the following
species greatly resemble the simplest forms of _Phractaspis_ (Pl. 137,
figs. 1, 2); they differ from these, however, by the equal size and
distance of the four branches of each spine, which thus form a rectangular
cross.
_Dimensions._--Diameter of the shell 0.1; breadth of the spines and bars
0.002.
_Habitat._--Central Pacific, Station 268, surface.
2. _Stauraspis xiphacantha_, n. sp.
Radial spines stout, cylindrical in the inner half, conical in the shorter
outer half. Four apophyses of each spine simple, not branched, broad, with
thick condyles. Meshes of the shell six to eight times as broad as the
bars.
_Dimensions._--Diameter of the shell 0.12; breadth of the spines and bars
0.008 to 0.01.
_Habitat._--South Pacific, Station 290, surface.
Subgenus 2. _Stauraspidium_, Haeckel.
_Definition._--Apophyses of the spines branched; therefore each spine with
eight to twenty or more sutural condyles.
{832}3. _Stauraspis furcata_, n. sp.
Radial spines thin, quadrangular, prismatic; outer and inner halves nearly
of equal length. The four apophyses of each spine simply forked (or partly
with bifid fork-branches); each spine with eight to twelve sutural
condyles. Meshes of the shell ten to twenty times as broad as the bars.
_Dimensions._--Diameter of the shell 0.15; breadth of the spines and bars
0.003.
_Habitat._--Central Pacific, Station 266, surface.
4. _Stauraspis stauracantha_, n. sp. (Pl. 137, figs. 5, 6).
Radial spines thin, in the inner longer half cylindrical, in the outer half
conical with thickened base. Four apophyses of each spine doubly forked or
dichotomously (more or less irregularly) branched; each spine with sixteen
to twenty-four sutural condyles. Meshes of the shell of very different
sizes and forms; the largest ten to fifteen, the smallest two to three
times as broad as the bars.
_Dimensions._--Diameter of the shell 0.14; breadth of of the spines 0.002
to 0.01, of the bars 0.002.
_Habitat._--Tropical Atlantic, Station 343, surface.
Genus 359. _Echinaspis_,[399] Haeckel, 1881, Prodromus, p. 467.
_Definition_--#Dorataspida# without perforated plates; shell composed only
of the meeting branches of the four crossed apophyses, which arise
(opposite in pairs) from each radial spine. Condyles of the branch-ends
bearing by-spines.
The genus _Echinaspis_ exhibits the same structure of the shell as its
ancestral form _Stauraspis_, and differs from it only in the development of
by-spines on the sutural condyli.
1. _Echinaspis dichotoma_, n. sp.
Radial spines cylindrical, thin, outer half longer than the inner. Four
apophyses of each spine simply forked (or partly with bifid fork-branches);
therefore each spine usually possesses eight (sometimes ten to twelve)
sutural condyles. Meshes of the shell ten to twelve times as broad as the
bars. Each condyle bears a zigzag by-spine, half as long as the radius.
_Dimensions._--Diameter of the shell 0.12, of the spines 0.004 to 0.006.
_Habitat._--North Pacific, Station 253, surface.
{833}2. _Echinaspis diadema_, n. sp.
Radial spines thin and long, quadrangular, prismatic; outer half two to
three times as long as the inner. Four apophyses of each spine simply
forked (or partly with bifid fork-branches); each spine with eight to
twelve sutural condyles. Meshes of the shell fifteen to twenty-five times
as broad as the bars. Each condyle bears a simple bristle-shaped by-spine,
nearly as long as the radius.
_Dimensions._--Diameter of the shell 0.11; breadth of the spines and bars
0.002.
_Habitat._--South Atlantic, Station 333, surface.
3. _Echinaspis echinoides_, n. sp. (Pl. 137, figs. 7,8).
Radial spines roundish, in the outer half conical, and two to three times
as broad as in the inner half. Four apophyses of each spine doubly forked
or dichotomously (more or less irregularly) branched; each spine with
sixteen to twenty-four sutural condyles. Meshes of the shell four to eight
times as broad as the bars. Each condyle bears a zigzag by-spine, one-third
as long as the radius.
_Dimensions._--Diameter of the shell 0.15; breadth of the spines 0.004 to
0.01, of the bars 0.002.
_Habitat._--Central Pacific, Station 266, surface.
Genus 360. _Zonaspis_,[400] n. gen.
_Definition._--#Dorataspida# with four plates, each of which is perforated
by four crossed aspinal pores; these four plates are formed by the united
branches of the other spines (eight polar and eight tropical) form no
lattice-plates by union. Each condyle bears a by-spine.
The genus _Zonaspis_ differs from all other Dorataspida in the peculiar
formation of the four equatorial spines, which form by union of the
recurved branches of their apophyses four perforated plates (each with four
crossed pores), whilst the branches of the sixteen other plates do not
unite to form plates, but simply meet the branches of the neighboring
spines.
1. _Zonaspis fragilis_, n. sp.
Radial spines very thin and long, cylindrical. Four meshes of each
equatorial plate pentagonal, ten to twelve times as broad as the bars.
By-spines zig-zag, nearly as long as the radius.
_Dimensions._--Diameter of the shell 0.16, of the parmal pores 0.018.
_Habitat._--South Atlantic, Station 332, surface.
{834}2. _Zonaspis cingulata_, n. sp. (Pl. 134, figs. 3, 4).
Radial spines cylindrical in the inner half, with thickened pyramidal bases
(fig. 3), conical in the outer half; both halves of equal length. The four
meshes of each equatorial plate egg-shaped, four to six times as broad as
the bars. By-spines zigzag, half as long as the radius.
_Dimensions._--Diameter of the shell 0.15, of the parmal meshes 0.015.
_Habitat._--Tropical Pacific (east coast off Philippines), Station 275,
surface.
3. _Zonaspis æquatorialis_, n. sp. (Pl. 135, fig. 5).
Radial spines stout, cylindrical in the shorter inner half, conical in the
longer outer half. The four meshes of each equatorial plate circular, only
twice as broad as the bars. By-spines zigzag, nearly as long as the radius.
_Dimensions._--Diameter of the shell 0.11, of the parmal meshes 0.008.
_Habitat._--Equatorial Atlantic, Station 347, surface.
Genus 361. _Dodecaspis_,[401] n. gen.
_Definition._--#Dorataspida# with twelve plates, each of which is
perforated by four crossed aspinal pores; these twelve plates are formed by
the united branches of the apophyses of four equatorial and eight polar
spines. The branches of the apophyses of the eight tropical spines form no
lattice-plates by union. Each condyle bears a by-spine.
The genus _Dodecaspis_ differs from all other Dorataspida in the peculiar
composition of its shell; twelve spines (four equatorial and eight polar
spines) form by union of the branches of their apophyses twelve plates,
each of which exhibits four crossed pores, whilst the eight other
(tropical) spines form no perforated plates, but simply unite with the
neighbouring spines by meeting branches. Some irregularity is often to be
found in this genus; instead of four pores in each plate there may be two
closed, the other two which are opposite being open. Several times I
observed a peculiar "hemihedral" variety: only six spines of one meridian
plane (the two equatorial and the four polar spines of the "hydrotomical"
plane) exhibited complete shields, whilst the branches of the other
fourteen plates remained open. This "hemihedral" form may perhaps represent
a peculiar genus, _Hemiaspis_.
1. _Dodecaspis tricinata_, n. sp. (Pl. 134, fig. 1).
Radial spines thin and long, cylindrical. The four meshes of each
equatorial and each polar plate of equal size, pentagonal, about eight
times as broad as the bars. By-spines zigzag, nearly as long as the radius.
In this species the hemihedral variety, _Hemiaspis_, often occurs.
_Dimensions._--Diameter of the shell 0.15, of the parmal pores 0.016.
_Habitat._--South-east Pacific (west coast of Patagonia), Station 302,
surface.
{835}2. _Dodecaspis trizonia_, n. sp.
Radial spines thin, cylindrical in the longer inner half, conical in the
shorter outer half. The four meshes of each equatorial and each polar plate
of equal size, roundish or nearly circular, five to six times as broad as
the bars. By-spines straight, denticulated, scarcely half as long as the
radius.
_Dimensions._--Diameter of the shell 0.12, of the parmal pores 0.012.
_Habitat._--South-west Pacific (east coast of New Zealand), Station 169,
surface.
B. Tribe II. #Lychnaspida#, Haeckel, 1881, Prodromus, p. 467.
_Definition._--#Dorataspida# with twenty perforated plates or fenestrated
shields (each plate at least with four pores), produced by union of the
branches of the four crossed apophyses, which arise, opposite in pairs,
from each radial spine. The spherical shell is composed of the twenty
plates united by sutures (rarely by concrescence).
Genus 362. _Tessaraspis_,[402] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
eighty aspinal pores (four crossed pores in each plate). Surface smooth,
without by-spines.
The genus _Tessaraspis_ introduces the series of Lychnaspida, which
comprise all those Dorataspida in which the shell is composed of twenty
plates, each of which is perforated by four primary aspinal pores. In
_Tessaraspis_ and _Lychnaspis_ each plate exhibits only these four primary
pores, whilst in _Icosaspis_ and _Hylaspis_ they become surrounded by a
circle of secondary or coronal pores. If in _Stauraspis_, the common
ancestral form of the Tessaraspida, the four crossed apophyses of each
single radial spine became recurved and united together, we should have the
typical plate of _Tessaraspis_, in which the piercing radial spine is
surrounded by four crossed pores of equal size. The number of sutural
pores, between the neighbouring plates, is variable; usually each plate is
surrounded by a circle of eight to twelve sutural pores. The sutures
between the meeting condyles of the apophyses usually remain open; but in
some species they become obliterated (subgenus _Tessaraspidium_).
Subgenus 1. _Tessarasparium_, Haeckel.
_Definition._--Condyles of the neighbouring plates connected by permanent
open sutures; therefore the whole shell is composed of twenty separated
pieces of acanthin.
{836}1. _Tessaraspis arachnoides_, n. sp. (Pl. 136, fig. 1).
Parmal pores pentagonal, ten to twenty times as broad as the thin
thread-like bars, on an average of about the same size as the irregular
sutural meshes; the majority of the latter are either triangular or
hexagonal. Radial spines very thin and long, cylindrical, their outer part
two to four times as long as the inner. As the insertion of the spines is
on the highest point of the plates, the shell becomes polyhedral
(dodecahedral?).
_Dimensions._--Diameter of the shell 0.15 to 0.17, of the parmal meshes
0.02 to 0.025, sutural meshes 0.01 to 0.03, bars 0.002.
_Habitat._--Equatorial Atlantic, Station 347, surface.
2. _Tessaraspis pentagonalis_, n. sp.
Parmal meshes pentagonal, three to four times as broad as the thick bars,
and on an average smaller than the irregular polygonal sutural meshes.
Radial spines stout, quadrangular; their outer pyramidal part shorter than
the inner prismatic part.
_Dimensions._--Diameter of the shell 0.12, of the parmal pores 0.01 to
0.012, bars 0.003.
_Habitat._--Central Pacific, Station 269, surface.
3. _Tessaraspis tetragonalis_, n. sp.
Parmal meshes tetragonal, or nearly square, six to eight times as broad as
the thin bars, and on an average larger than the irregular polygonal
sutural meshes. Radial spines thin, quadrangular, prismatic, their outer
part longer than their inner.
_Dimensions._--Diameter of the shell 0.16, of the parmal pores 0.012 to
0.016, bars 0.002.
_Habitat._--South Pacific, Station 288, surface.
4. _Tessaraspis hexagonalis_, n. sp.
Parmal meshes hexagonal, ten to twelve times as broad as the thin bars, and
on an average larger than the polygonal sutural meshes (the two proximal
sides of each hexagonal parmal mesh two to three times as long as the four
distal sides). Radial spines cylindrical, thin; their outer part longer
than the inner.
_Dimensions._--Diameter of the shell 0.15, of the parmal pores 0.01 to
0.015, bars 0.001.
_Habitat._--North Pacific, Station 254, surface.
5. _Tessaraspis trigonalis_, n. sp.
Parmal meshes triangular, three to four times as broad as the thick bars,
and on an average smaller than the irregular sutural meshes (in each plate
all four parmal meshes of the same size, formed like an isosceles triangle,
the distal base of which is somewhat curved, and convex towards {837}the
periphery, whilst the two proximal sides are straight). Radial spines
thick, rounded; their outer conical part shorter than the inner cylindrical
part.
_Dimensions._--Diameter of the shell 0.1, of the parmal pores 0.01, of the
sutural pores 0.01 to 0.02.
_Habitat._--Tropical Atlantic (near Ascension), Station 345, depth 2010
fathoms.
6. _Tessaraspis circularis_, n. sp.
Parmal meshes circular, all eighty of equal size, quite regular, five to
six times as broad as the thick bars, on an average larger than the
roundish irregular sutural meshes. Radial spines quadrangular, prismatic,
the outer part longer than the inner.
_Dimensions._--Diameter of the shell 0.18, parmal pores 0.015 to 0.018,
bars 0.003.
_Habitat._--South-east Pacific, Station 300, surface.
7. _Tessaraspis micropora_, n. sp.
Parmal meshes circular, very small, all eighty of the same size, regular,
scarcely as broad as the separating thick bars, and much smaller than the
large irregular sutural meshes. Radial spines rounded, their outer conical
part about as long as the inner cylindrical part.
_Dimensions._--Diameter of the shell 0.08, of the parmal pores 0.003, of
the sutural pores 0.005 to 0.015, bars 0.004.
_Habitat._--Western Tropical Pacific, Station 225, surface.
8. _Tessaraspis diodon_, Haeckel.
_Dorataspis diodon_, Haeckel, 1862, Monogr. d. Radiol., p. 417, Taf.
xxii. figs. 1-5.
Parmal meshes roundish, for the most part nearly circular, three to four
times as broad as the bars, and on an average smaller than the roundish
sutural meshes. Radial spines in the inner part cylindrical; the outer part
very short (only one-third or one-fourth of the radius), divided completely
into two parallel conical pointed teeth by a deep incision.
_Dimensions._--Diameter of the shell 0.12, of the parmal pores 0.01 to
0.012, of the sutural pores 0.01 to 0.03, bars 0.004.
_Habitat._--Mediterranean (Messina), surface.
9. _Tessaraspis quadriforis_, n. sp.
Parmal meshes irregular, roundish, of nearly equal size, four to six times
as broad as the bars, and on an average of the same size as the roundish
sutural meshes. Radial spines quadrangular, prismatic in the inner part,
which is somewhat longer than the conical outer part.
_Dimensions._--Diameter of the shell 0.16, of the pores 0.012 to 0.018,
bars 0.003.
_Habitat._--North Atlantic, Canary and Cape Verde Islands, Station 353,
surface.
{838}10. _Tessaraspis irregularis_, n. sp.
Parmal meshes irregular, roundish, of unequal size, three to six times as
broad as the bars, and on an average larger than the irregular sutural
meshes. Radial spines cylindrical, the outer part longer than the inner
part.
_Dimensions._--Diameter of the shell 0.13, parmal pores 0.006 to 0.012,
sutural pores 0.005 to 0.01; bars 0.002.
_Habitat._--Central Pacific, Station 270, surface.
Subgenus 2. _Tessaraspidium_, Haeckel.
_Definition._--Condyles of the neighbouring plates grown together and
sutures obliterated; therefore the whole shell forms a single piece of
acanthin.
11. _Tessaraspis quadrata_, n. sp.
_Tessaraspidium quadratum_, Haeckel, 1882, Manuscript.
Parmal meshes square, four times as broad as the thin bars, on an average
of the same size as the polygonal sutural meshes. Radial spines stout,
tetrapterous, prismatic, in the outer part longer than in the inner.
Sutures of the shell completely obliterated, therefore the whole shell
forms one piece.
_Dimensions._--Diameter of the shell 0.16, of the parmal pores 0.012,
sutural pores 0.01 to 0.015.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
12. _Tessaraspis rotunda_, n. sp.
Parmal meshes circular, of equal size, twice as broad as the thick bars, on
an average smaller than the roundish sutural meshes. Radial spines
cylindrical in the inner part, which is somewhat longer than the outer
conical part. Sutures of the shell completely obliterated, therefore the
whole shell forms one piece.
_Dimensions._--Diameter of the shell 0.12, parmal pores 0.008, sutural
pores 0.005 to 0.015.
_Habitat._--North Atlantic, Station 354, surface.
13. _Tessaraspis concreta_, n. sp. (Pl. 136 fig. 5).
Parmal meshes irregular, polygonal or roundish, six to eight times as broad
as the narrow and high bars, much larger than the irregular sutural meshes.
Radial spines leaf-shaped, compressed, two-edged, pointed at both ends;
inner and outer part nearly of equal size. Shell very thick walled; meshes
therefore funnel-shaped; sutures completely obliterated, therefore the
whole shell forms a single piece.
_Dimensions._--Diameter of the shell 0.09, parmal pores 0.02, sutural pores
0.01.
_Habitat._--Central Pacific, Station 274, depth 2750 fathoms.
{839}Genus 363. _Lychnaspis_,[403] Haeckel, 1862, Prodromus, p. 468.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
eighty aspinal pores (four crossed pores in each plate). Surface covered
with numerous by-spines.
The genus _Lychnaspis_, the largest and most common of all Dorataspida,
exhibits the same structure of the shell as its ancestral form
_Tessaraspis_, and differs from it only in the development of by-spines on
the sutural condyles. Many species of this genus are very widely
distributed, and appear in large numbers, and some of them are amongst the
most graceful and elegant of the Radiolaria.
Subgenus 1. _Lychnasparium_, Haeckel.
_Definition._--Condyles of the neighbouring plates connected by permanent
open sutures; therefore the whole shell is composed of twenty separate
pieces of acanthin.
1. _Lychnaspis giltschii_, n. sp. (Pl. 135, fig. 3).
Parmal meshes pentagonal, about ten or twelve times as broad as the thin
bars, on an average of the same size as the irregular polygonal sutural
meshes. By-spines (two hundred to three hundred) very delicate, half as
long as the radius, barbed, and zigzag. Radial main-spines very thin and
long, straight, cylindrical; their outer part longer than the inner part.
_Dimensions._--Diameter of the shell 0.2, of the parmal pores 0.02, sutural
pores 0.01 to 0.03, bars 0.002.
_Habitat._--Tropical Atlantic, Stations 338 to 348, surface.
2. _Lychnaspis capillaris_, n. sp.
Parmal meshes pentagonal, twenty to thirty times as broad as the very thin
thread-like bars, on an average of the same size as the irregular polygonal
sutural meshes. By-spines (two hundred to two hundred and fifty) very
delicate, zigzag, with very small denticles, one-third as long as the
radius. Radial main-spines very thin and long, cylindrical, more or less
undulated.
_Dimensions._--Diameter of the shell 0.25, parmal pores 0.025, sutural
pores 0.02 to 0.04, bars 0.001.
_Habitat._--North Pacific, Station 250, surface.
3. _Lychnaspis maxima_, n. sp.
Parmal meshes pentagonal, six to eight times as broad as the thick bars,
for the most part larger than the irregular sutural meshes. By-spines
(four hundred to five hundred) nearly as {840}long as the radius,
zigzag, with short denticles. Radial spines very long and stout,
quadrangularly-prismatic, with four smooth edges.
_Dimensions._--Diameter of the shell 0.3, parmal pores 0.03, sutural pores
0.01 to 0.025, bars 0.004.
_Habitat._--Central Pacific, Stations 271 to 274, surface.
4. _Lychnaspis serrata_, n. sp.
Parmal meshes pentagonal, three to four times as broad as the thick bars,
smaller than the irregular sutural meshes. By-spines (two hundred to three
hundred) scarcely one-third as long as the radius, zigzag, with strong
denticles. Radial spines very long, stout, quadrangularly-prismatic, with
four serrated edges.
_Dimensions._--Diameter of the shell 0.22, parmal pores 0.015, sutural
pores 0.012 to 0.03, bars 0.004.
_Habitat._--South Atlantic, Station 330, surface.
5. _Lychnaspis wagenschieberi_, n. sp.
Parmal meshes tetragonal, nearly rhombic, three to four times as broad as
the thick bars, smaller than the large irregular sutural meshes. By-spines
(about two hundred) large, as long as the radius, with long recurved
denticles, very zigzag. Radial main-spines very long, four-sided prismatic.
This species differs by the form and size of the spines, and by the square
form of the parmal pores from the similar _Lychnaspis polyancistra_, of
which the late excellent engraver Wagenschieber, of Berlin, has given such
a beautiful figure in my monograph (Taf. xxi. fig. 8).
_Dimensions._--Diameter of the shell 0.16, parmal pores 0.014, sutural
pores 0.015 to 0.02, bars 0.004.
_Habitat._--Central Pacific, Station 266, surface.
6. _Lychnaspis polyancistra_, Haeckel.
_Dorataspis polyancistra_, Haeckel, 1862, Monogr. d. Radiol., p. 418,
Taf. xxi. figs. 7-9.
Parmal meshes roundish, tetragonal, or nearly square, two to three times as
broad as the thick bars, smaller than the irregular sutural meshes.
By-spines (about two hundred) thin, half as long as the radius, zigzag,
with blunt denticles. Radial main-spines stout, in the inner half
cylindrical, in the outer half (of the same length) conical, pointed.
_Dimensions._--Diameter of the shell 0.12, parmal pores 0.012, sutural
pores 0.01 to 0.04, bars 0.004.
_Habitat._--Mediterranean (Messina), surface.
{841}7. _Lychnaspis rottenburgii_, n. sp. (Pl. 135, fig. 4).
Parmal meshes roundish, about twice as broad as the thick bars, and for the
most part smaller than the irregular sutural meshes. By-spines (about two
hundred to two hundred and fifty) thin, zigzag, half as long as the radius.
Radial main-spines very strong, cylindrical in the inner half, in the outer
half much thicker and conical, pointed. I call this species in honour of my
learned friend, the great patron of zoological studies, Mr. Paul
Rottenburg, of Glasgow.
_Dimensions._--Diameter of the shell 0.15, parmal pores 0.012, sutural
pores 0.01 to 0.03, bars 0.006.
_Habitat._--Central Pacific, Station 270, depth 2925 fathoms.
8. _Lychnaspis undulata_, n. sp. (Pl. 135, fig. 2).
Parmal meshes circular, twice as broad as the thick bars, on an average of
the same size as the irregular sutural meshes. By-spines (one hundred and
fifty to two hundred) very thin, barbed and zigzag, as long as the radius.
Radial main-spines cylindrical; their outer pointed part longer than the
inner part.
_Dimensions._--Diameter of the shell 0.1, parmal pores 0.01, sutural pores
0.01, bars 0.005.
_Habitat._--Tropical Atlantic, Station 343, surface.
9. _Lychnaspis longissima_, n. sp. (Pl. 134, fig. 6).
Parmal meshes circular, very small, of the same breadth as the thick bars,
much smaller than the irregular sutural meshes. By-spines (one hundred to
one hundred and ten) very long and thin, zigzag, twice as long as the
diameter of the shell. Radial main-spines very long and strong, cylindrical
(at the base quadrangular, pyramidal), four to six times as long as the
diameter of the shell, and one fourth as thick as its radius.
_Dimensions._--Diameter of the shell 0.08, parmal pores 0.002, sutural
pores 0.01 to 0.015, bars 0.003; length of the radial spines 0.3 to 0.5.
_Habitat._--Tropical Pacific (Philippines), Stations 200 to 215, surface.
10. _Lychnaspis minima_, n. sp. (Pl. 134, figs. 2, 7, 8).
Parmal meshes circular, very small, only half as broad as the thick bars,
much smaller than the irregular sutural meshes. By-spines (one hundred to
one hundred and ten) half as long as the radius, zigzag. Radial main-spines
thick, in the inner part cylindrical, in the outer shorter part conical, of
very variable size.
_Dimensions._--Diameter of the shell 0.05, parmal pores 0.002, sutural
pores 0.006 to 0.012, bars 0.004.
_Habitat._--Antarctic Ocean, Station 154, surface.
{842}Subgenus 2. _Lychnaspidium_, Haeckel.
_Definition._--Condyles of the neighbouring plates grown together and
sutures obliterated, therefore the whole shell forms a single piece of
acanthin.
11. _Lychnaspis echinoides_, Haeckel.
_Haliomma echinoides_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p.36, Taf. v. figs. 3, 4.
_Haliommatidium echinoides_, J. Müller, 1858, Abhandl. d. k. Akad. d.
Wiss. Berlin, p. 22.
_Haliommatidium echinoides_, Haeckel, 1862, Monogr. d. Radiol., p. 422.
Parmal meshes pentagonal or somewhat roundish, four times as broad as the
bars, and of about the same size as the polygonal meshes. By-spines (about
two hundred) short, zigzag. Radial spines thin; their outer conical part
shorter than the inner cylindrical part. Sutures perfectly obliterated, but
recognisable by the characteristic pair of divergent by-spines. (Some
recent observations on this species, made during 1880 in Portofino, have
convinced me that the interpretation of it given in my Monograph, 1862,
_loc. cit._, was quite correct.)
_Haliomma ligurinum_, J. Müller (= _Haliommatidium ligurinum_, Haeckel, L.
N. 16, p. 423) seems to be closely allied to the preceding.
_Dimensions._--Diameter of the shell 0.12 to 0.14, parmal pores 0.015,
sutural pores 0.01 to 0.02, bars 0.004.
_Habitat._--Mediterranean, Nice, Saint Tropez (J. Müller); Portofino near
Genoa (Haeckel).
12. _Lychnaspis haliommidium_, n. sp.
_Lychnaspidium haliommidium_, Haeckel, 1882, Manuscript.
Parmal meshes circular, twice as broad as the bars, smaller than the
irregular sutural meshes. By-spines (about two hundred) barbed and zigzag,
as long as the radius. Radial main-spines four-sided; their outer pyramidal
part shorter than the inner prismatic part. Sutures perfectly obliterated.
_Dimensions._--Diameter of the shell 0.1, parmal pores 0.01, sutural meshes
0.015 to 0.02.
_Habitat._--South Atlantic, Station 335, depth 1425 fathoms.
13. _Lychnaspis rabbeana_, n. sp.
Parmal meshes circular, very small, of the same breadth as the bars, and
much smaller than the irregular sutural meshes. By-spines (about one
hundred) very long and thin, zigzag, about as long as the diameter of the
shell. Radial main-spines cylindrical, thick, twice to three times as long
as the diameter of the shell. Sutures perfectly obliterated, with thickened
condyles. Named in honour of Captain Henrik Rabbe (of Bremen), to whom I am
indebted for many new Indian and Atlantic Radiolaria.
_Dimensions._--Diameter of the shell 0.086, parmal pores 0.002, sutural
pores 0.012, bars 0.002.
_Habitat._--Indian Ocean (Madagascar), Rabbe, surface.
{843}14. _Lychnaspis cataplasta_, n. sp.
Parmal pores very small, circular, half as broad as the bars, and much
smaller than the irregular sutural pores. By-spines zigzag, as long as the
diameter of the shell. Radial main-spines very thin and long,
needle-shaped, cylindrical, five to six times as long as the diameter of
the shell. Sutures perfectly obliterated. (This stunted species is one of
the smallest of the Dorataspida.)
_Dimensions._--Diameter of the shell 0.05, parmal pores 0.0015, sutural
pores 0.01, bars 0.002.
_Habitat._--Antarctic Ocean (off Kerguelen Island), Station 149, surface.
Genus 364. _Icosaspis_,[404] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
one hundred and sixty to three hundred or more parmal pores (in each plate
four crossed aspinal pores, and around them four to twelve or more coronal
pores). Surface without by-spines.
The genus _Icosaspis_ and the closely allied _Hylaspis_ differ from all
other Tessaraspida in the increased number of the parmal pores. Whilst this
number in all other genera is eighty (only four crossed pores in each
plate), here it amounts to one hundred and sixty to three hundred or more
(sometimes more than a thousand); in each shield four primary, crossed
"aspinal pores" being surrounded by a circle of four to twelve or more
"coronal pores." The number of sutural pores in these two genera is also
increased.
Subgenus 1. _Icosasparium_, Haeckel.
_Definition._--Condyles of the neighboring plates connected by permanent
open sutures; therefore the whole shell composed of twenty separated pieces
of acanthin.
1. _Icosaspis tabulata_, n. sp. (Pl. 136, fig. 2).
Parmal meshes all of nearly equal size and form, square, four times as
broad as the bars, little larger than the triangular or polygonal sutural
meshes. In each plate fifty to seventy (regularly sixty-four) quadrangular
pores, viz., four primary square aspinal meshes, forming together a regular
square surrounded by two to three coronas of rectangular (not quite
regular) coronal meshes (six to eight in each transverse row). Radial
spines tetrapterous, prismatic, with four thin and broad wings, from which
arise the crossed bars between the four primary pores. Outer part of the
spines longer than the inner. Commonly the condyles of the plates are only
contiguous; sometimes they grow together, and this form approaches
_Icosaspis tetragonopa_.
_Dimensions._--Diameter of the shell 0.25 to 0.3, of the pores 0.02, bars
0.005.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
{844}2. _Icosaspis elegans_, n. sp. (Pl. 136, fig. 4; Pl. 134, fig. 9).
_Tessaraspis elegans_, Haeckel, 1882, Manuscript et Atlas.
Parmal meshes of very different size and form; in the centre of each plate
a cross of four primary, pear-shaped "aspinal pores" (the largest of all);
between them four secondary, little smaller, crossed, egg-shaped "angular
pores"; around this rosette of eight larger meshes an inner complete circle
of sixteen to twenty polygonal coronal pores, and an outer incomplete
circle of thirty to forty very small marginal pores. The latter are smaller
than the irregular sutural meshes, which are constricted in the middle,
about forty to sixty around each plate. Radial spines thin, cylindrical, or
a little compressed; their outer part longer than the inner. In this
elegant and very common species the condyles usually remain separated by
sutures; but sometimes the latter become obliterated, and the whole shell
then forms a single piece, _Icosaspidium elegans_.
_Dimensions._--Diameter of the shell 0.2 to 0.3, commonly 0.25; larger
parmal pores 0.02, smaller 0.001 to 0.003; sutural pores 0.005 to 0.015;
bars 0.003.
_Habitat._--Tropical and Subtropical Atlantic, Canary Islands to Ascension
Island, Stations 340 to 354, surface.
3. _Icosaspis cruciata_, n. sp. (Pl. 134, fig. 10).
Parmal meshes very different; in the centre of each plate a cross of four
primary, nearly oblong, rectangular "aspinal pores"; between these four
secondary, triangular, egg-shaped "angular pores" (the largest of all), and
around this rosette a single circle of twelve to twenty-four small "coronal
pores." The latter are of about the same size as the irregular sutural
meshes, of which there are twenty to thirty around each plate. Radial
spines thin, cylindrical, or a little compressed; their outer part longer
than the inner.
_Dimensions._--Diameter of the shell 0.2 to 0.3, commonly 0.25; larger
parmal pores 0.025, smaller 0.005 to 0.01; bars 0.005.
_Habitat._--Tropical and Subtropical Pacific, Sandwich to Marquesas
Islands, Stations 256 to 274, surface.
4. _Icosaspis ornata_, n. sp.
Parmal meshes very different; in the centre of each plate a cross of four
primary octagonal aspinal pores (the largest of all); between them four
secondary, rhombic angular pores, and around this rosette a circle of
twelve to sixteen smaller, polyhedral coronal pores, which are however
larger than the irregular sutural pores (surrounding each plate to the
number of twenty to thirty). Radial spines thin, quadrangular, prismatic;
the outer part longer than the inner.
_Dimensions._--Diameter of the shell 0.25; larger parmal pores 0.03,
smaller 0.01; sutural pores 0.004 to 0.008; bars 0.006.
_Habitat._--South Pacific, Station 295, depth 1500 fathoms.
{845}5. _Icosaspis spectabilis_, n. sp.
Parmal meshes very different; in the centre of each plate four very large,
pentagonal aspinal pores, and around these two to three circles of smaller
polygonal coronal pores, which are very numerous, and not larger than the
small sutural pores. Radial spines quadrangular, prismatic, stout, very
long; the outer part two to three times as long as the inner.
_Dimensions._--Diameter of the shell 0.4, of the larger aspinal meshes
0.03, of the outer meshes 0.002 to 0.02, bars 0.005.
_Habitat._--South Atlantic, Station 333, surface.
6. _Icosaspis multiforis_, n. sp.
Parmal meshes very numerous, more than one hundred in each plate; in the
centre four larger pear-shaped pores, and around these four to five circles
of smaller pores, gradually smaller towards the margin of the plate; the
sutural meshes also very small and numerous (more than fifty around each
plate), so that the number of all the pores together amounts to two
thousand or even more. Radial spines thin, cylindrical, very long.
_Dimensions._--Diameter of the shell 0.32; larger aspinal pores 0.02,
smaller 0.002 to 0.01; bars 0.003.
_Habitat._--Indian Ocean (Madagascar), Rabbe, surface.
Subgenus 2. _Icosaspidium_, Haeckel.
_Definition._--Condyles of the neighbouring plates grown together, and
sutures obliterated; therefore the whole shell forms a single piece of
acanthin.
7. _Icosaspis tetragonopa_, Haeckel.
_Haliommatidium tetragonopum_, Haeckel, 1862, Monogr. d. Radiol., p.421,
Taf. xxii. fig. 13.
Parmal meshes all of nearly equal size and form, square, three times as
broad as the bars, little larger than the sutural meshes. In each plate
commonly sixteen equal square meshes, viz., four primary aspinal and twelve
secondary, surrounding the former as a square corona. Radial spines
tetrapterous, stout; the outer pyramidal half somewhat longer than the
inner. This species differs from the similar _Icosaspis tabulata_ (Pl. 136,
fig. 2) in the concrescence of the sutures, the smaller number of pores,
and the form of the stouter spines. The figure in my Monograph, drawn from
a broken fragment, is not quite correct.
_Dimensions._--Diameter of the shell 0.18, pores 0.009, bars 0.003.
_Habitat._--Mediterranean (Messina, Corfu), surface.
8. _Icosaspis icosahedra_, n. sp.
Parmal meshes of different size and form; in the centre of each plate a
cross of four pentagonal, primary aspinal pores, surrounded by a complete
corona of twelve to sixteen polygonal coronal {846}pores and an incomplete
corona of thirty to forty very small marginal pores; the latter are not to
be distinguished from the pores of the obliterated sutures. Radial spines
quadrangular, the outer pyramidal part shorter than the inner prismatic
part. Condyles grown together. As the plates are quite even, the shell
becomes icosahedral.
_Dimensions._--Diameter of the shell 0.16, pores 0.002 to 0.02, bars 0.005.
_Habitat._--North Pacific, Station 241, surface.
9. _Icosaspis icosastaura_, n. sp. (Pl. 136, fig. 3).
_Tessaraspis icosastaura_, Haeckel, 1882, Manuscript et Atlas.
Parmal plates of different size and form; in the centre of each plate a
cross of four larger primary, pyriform aspinal pores; between these four
smaller roundish angular pores, and around this rosette a circle of ten to
twenty (commonly sixteen) coronal pores, little larger than the very small
sutural pores. Radial spines very thin and long, cylindrical or
bristle-shaped. Condyles grown together; no suture visible.
_Dimensions._--Diameter of the shell 0.14; larger pores of the cross 0.01,
smaller pores 0.002 to 0.008; bars 0.002 to 0.004.
_Habitat._--Central Pacific, Station 268, surface.
Genus 365. _Hylaspis_,[405] n. gen.
_Definition._--#Dorataspida# with twenty plates, which are perforated by
one hundred and sixty to three hundred or more parmal pores (in each plate
four crossed aspinal pores, and around them four to twelve or more coronal
pores). Surface covered with numerous by-spines.
The genus _Hylaspis_ exhibits the same structure of the shell as the nearly
allied ancestral genus _Icosaspis_, and differs from it only in the
development of by-spines. Some species of these two genera exhibit the
highest degree of complication in the structure of the shell seen among the
Dorataspida.
1. _Hylaspis serrulata_, n. sp. (Pl. 135, fig. 1).
Parmal meshes four hundred to five hundred; in the centre of each plate a
cross of four very large pentagonal or roundish aspinal pores, and around
this a circle of sixteen to twenty much smaller irregular, polygonal,
coronal pores; the latter of about the same size as the sutural pores. On
each condyle one thin zigzag-shaped by-spine, nearly as long as the radius.
Twenty radial spines very long, quadrangular, prismatic; on the inside
thinner and smooth, on the outside thickened, and armed with four rows of
recurved teeth, serrated.
_Dimensions._--Diameter of the shell 0.18, aspinal spines 0.02, other pores
0.002 to 0.01, bars 0.003.
_Habitat._--South Atlantic, Station 326, surface.
{847}2. _Hylaspis coronata_, n. sp.
Parmal meshes five hundred to six hundred; in the centre of each plate a
cross of four long rectangular aspinal pores, between these four larger
egg-shaped angular pores; around this rosette a circle of sixteen to twenty
much smaller, irregular, roundish, coronal pores; the latter about of the
same size as the sutural pores. On each condyle one bearded by-spine about
one-third or one-fourth as long as the radius. Twenty radial spines, very
long, smooth, quadrangular, prismatic.
_Dimensions._--Diameter of the shell 0.25, aspinal pores 0.02, other pores
0.005 to 0.01, bars 0.004.
_Habitat._--Central Pacific, Station 271, surface.
3. _Hylaspis barbata_, n. sp.
Parmal meshes twelve hundred to sixteen hundred; in the centre of each
plate a cross of four large, somewhat oblong, octahedral aspinal pores,
between these four rhombic smaller angular pores; around this rosette an
inner circle of twelve to sixteen larger and an outer circle of fifty to
sixty very small coronal pores; the latter smaller than the sutural pores.
On each condyle one bristle-shaped zigzag by-spine, with recurved thin
hooks, half as long as the radius. Twenty radial spines, very long,
cylindrical, smooth.
_Dimensions._--Diameter of the shell 0.25 to 0.3, aspinal pores 0.022,
other pores 0.002 to 0.015, bars 0.002.
_Habitat._--South Pacific, Station 295, surface.
Family XLI. #PHRACTOPELTIDA#, Haeckel (Pl. 133, figs. 1-6).
_Phractopeltida_, Haeckel, 1881, Prodromus, p. 468.
_Definition._--ACANTHARIA with double spherical lattice-shell, composed of
the branched apophyses of twenty radial spines meeting in its centre, and
disposed according to the Müllerian law of Icosacantha. Central capsule
spherical, enclosing the inner and surrounded by the outer concentric
shell.
The family #Phractopeltida# differs from all other ACANTHARIA in the
development of a double spherical shell, composed of two concentric
lattice-spheres, which are united by twenty radial spines meeting in the
common centre. We could therefore oppose the Phractopeltida as
_Diplophracta_ to all other #Acanthophracta# as _Haplophracta_ (with simple
shell). The former exhibit a relation to the latter, similar to that
exhibited by the Dyosphærida to the simple Monosphærida among the
#Sphæroidea#.
In my Monograph (1862, p. 423) I described only one genus appertaining to
this family, _Aspidomma_. I founded it upon the singular _Phractopelta_,
described by {848}J. Müller as _Haliomma hystrix_. A second species of
_Aspidomma_, the _Acanthometra mucronata_ of J. Müller, was probably an
_Astrolonche_. At that time I placed _Aspidomma_ among the Haliommatida,
led by the erroneous opinion that it might represent a transition-form
between _Dorataspis_ and _Haliomma_. But I afterwards gave up this view, as
I was convinced that there is no true phylogenetic connection between the
acanthinic Dorataspida (_Actipylea_) and the siliceous Haliommatida
(_Peripylea_). Therefore in my Prodromus (1881, p. 468) I placed
_Aspidomma_ among the Dorataspida and changed its name to _Phractopelta_,
to avoid further confusion with the unrelated Ommatida (#Sphæroidea#). It
formed there, with three nearly related genera, the "subfamily
Phractopeltida," which we now advance to the higher rank of a separate
family. (By a typographical mistake the words are printed in the Prodromus
_Phractopelma_ and Phractopelmida, &c., instead of _Phractopelta_ and
Phractopeltida, &c.). The detection of other new species appertaining to
this family, and a closer anatomical investigation of them, has now led to
the distinction of five different genera, characterised by other
differences than were employed in 1881 in the provisional system of the
"Prodromus."
The two concentric spherical lattice-shells of the Phractopeltida,
connected by radial beams, correspond perfectly to those of the
double-shelled Dyosphærida (_Haliomma_, _Diplosphæra_, &c.), and in both
cases we may call the smaller inner the "medullary shell," and the larger
outer the "cortical shell." There is no doubt that the double-shelled
Phractopeltida must be derived phylogenetically from the simple-shelled
Dorataspida (just as we derive the double Dyosphærida from the simple
Monosphærida). But it is not yet possible to decide positively which of the
two shells is the first formed. Probably the small inner or medullary shell
of the Phractopeltida is the first formed, and corresponds to the simple
spherical lattice-shell of the Dorataspida; and the larger outer or
cortical shell of the former is a later new formation, absent in the latter
family. This opinion seems to be confirmed by the genus _Orophaspis_, the
only form among the Dorataspida, in which the radial spines outside the
shell bear free latticed apophyses. If these twenty apophyses grow further
and meet one another, the second or outer shell of _Phractopelta_ may be
formed. But some objections may be raised to this opinion from the peculiar
structure and the very small size of the inner shell; and there is some
possibility that this latter is a secondary later product inside of the
primary cortical shell. The probably phylogenetic series which reveals the
origin of the Phractopeltida is the following:--_Acanthometron_,
_Zygacantha_, _Lithophyllium_, _Phractacantha_, _Doracantha_, _Dorataspis_,
_Orophaspis_, _Phractopelta_.
The twenty radial spines exhibit in all Phractopeltida the same
characteristic position and relation as in all other Icosacantha, and are
constantly arranged according to the Müllerian law in four meridian planes,
their distal ends falling into five parallel zones. Their distinction in
the majority of the Phractopeltida is not difficult, {849}since the spines
of the different zones bear apophyses of different shapes. Sometimes the
four equatorial spines are stouter than the sixteen other spines, and often
the eight tropical spines are somewhat different in form from the eight
polar and from the four equatorial spines. The length of all twenty spines
is commonly equal. Their form is usually more or less compressed, two-edged
(as in _Zygacantha_), more rarely cylindrical (as in _Acanthometron_), or
somewhat quadrangular (but not truly prismatic); therefore the transverse
section of the spines is commonly elliptical or lanceolate, rarely circular
or rhombic, never square; this seems to indicate their origin from
_Zygacantha_. As in all ACANTHARIA, the spines consist of acanthin, not of
silex. Their central ends are either perfectly grown together, and form a
single star of acanthin, or the triangular faces of their small pyramidal
bases are supported one upon another, without true concrescence.
The apophyses of the radial spines, by which the two concentric spherical
shells are formed, seem to be constantly four on each spine, two being
opposite in each shell. The proximal pair of opposite apophyses, forming
the inner or medullary shell, is constantly much smaller than the distal
pair composing the outer or cortical shell (Pl. 133, fig. 5). The proximal
pair corresponds probably to the two primary apophyses of the Diporaspida
(_Phractaspis_, _Dorataspis_, &c.), whilst the distal pair corresponds to
the free apophyses of _Orophaspis_ (Pl. 133, fig. 6). Therefore the
Phractopeltida may be derived phylogenetically from the Diporaspida (not
from the Tessaraspida). In the common ancestral genus of this family,
_Phractopelta_, the free part of the radial spines (outside the outer
shell) is quite simple, without free apophyses; in all other genera of the
family that free part of the spines (either in all twenty spines or only in
some of them) bears a third pair of lateral apophyses; these may be either
simple or branched or even latticed; but the outer apophyses (of the third
rank) remain constantly free, and a third lattice-shell is never formed by
union of their edges (Pl. 133, figs. 2-4).
The inner lattice-shell of the Phractopeltida, or their "medullary shell,"
is constantly very small (commonly 0.03 to 0.05 mm. in diameter, rarely
more). Its structure is difficult to make out; in the unbroken shell it is
concealed by the dense network of the outer shell; in the broken shell it
is commonly destroyed. Usually the pores of the inner shell are very small,
circular or subcircular, scarcely as broad as the small separating bars. In
the majority of Phractopeltida their number seems to be about forty, being
probably the forty primary aspinal pores of the Diporaspida; in some
species this number seems to be exceeded, so that perhaps some sutural
pores may exist between the aspinal pores; but commonly the twenty plates
composing the inner shell (each with two aspinal pores) seems to grow
together perfectly by their meeting edges, so that there are no sutural
pores between them. Evident sutures were not recognisable in the inner
shell of any Phractopeltida.
{850}The outer lattice-shell of the Phractopeltida, or their "cortical
shell," is at least twice as broad, commonly about three times as broad, as
the enclosed inner shell; it is much more varied in composition than the
latter. Like the greater part of the Dorataspida we may distinguish here in
the lattice-work two kinds of pores--parmal pores and sutural pores. The
parmal pores are produced by the union of the meeting branches of the
apophyses of each single spine, and are therefore visible on each isolated
spine; whilst the sutural pores are formed by the meeting branches of the
apophyses of neighbouring spines. The distinction of the parmal and the
sutural pores, easy in most Dorataspida, is difficult in most
Phractopeltida, because the sutures between the meeting branches are
usually very early obliterated. However, the place of the obliterated
suture is often indicated by the thickened condyles of the apophyses on
both sides of the suture. Commonly also the form of the sutural pores is
much more irregular than that of the parmal pores; the former are more or
less constricted in the middle by the intumescence of the sutural condyles,
whilst the latter are more roundish, elliptical, kidney-shaped, or square.
The number of the pores in the outer shell in the typical normal form of
Phractopeltida seems to be the same as in the most species of _Dorataspis_,
_Diporaspis_, &c., between ninety and one hundred, viz., forty parmal pores
and from fifty to sixty sutural pores. However, in many species this number
is increased. Since in all Phractopeltida, each of the twenty plates is
composed only of the meeting branches of two opposite apophyses, we find
originally in each plate only two primary parmal pores or "aspinal pores."
But in some species there occur four, six, or more pores in each plate; in
this case two of them only are aspinal pores, all the others being "coronal
pores." Moreover, in those species which exhibit on the base of each spine
in the outer shell four crossed pores (Pl. 133, fig. 2), there are not four
equivalent aspinal pores (as in the Tessaraspida), but the two opposite are
primary or aspinal pores and the other two (different from them in size and
form) coronal pores. However, the number of coronal pores in the
Phractopeltida is never so large as in many Dorataspida, and the same holds
good also for the increasing number of the irregular sutural pores. In none
of the species observed does the total number of the pores in the outer
shell reach two hundred.
The original mode of development of the apophyses composing the outer shell
seems to be imitated by the free apophyses of the third order, which are
developed from the radial spines outside the outer shell in all
Phractopeltida, with the single exception of the simple ancestral genus
_Phractopelta_. These apophyses of the third rank are also originally
constantly two, opposite to one another (after the type of _Lithophyllium_,
_Dorataspis_, &c.). Commonly they do not remain simple, but become
branched, and by communication of the neighbouring branches small
lattice-plates arise. Originally each of these free lattice-plates has only
two parmal pores, but the number of the parmal pores increases afterwards,
so that we may distinguish two (primary) {851}aspinal pores, and two,
four, or more (secondary) coronal pores. In the majority of species the two
opposite apophyses are first crossed at right angles by a transverse beam,
and the two parallel transverse beams are again crossed by perpendicular
tertiary branches (again parallel to the apophyses). In this case the
network of the free lattice-plates becomes more or less rectangular. But in
other species the ramification of the apophyses assumes more the form of
bifurcation or of irregular branching. As already said, the neighbouring
free lattice-plates of this third order never meet, and therefore a
complete third shell is never formed.
The different genera of Phractopeltida exhibit very remarkable differences
in the development of free apophyses (or lattice-plates of the third
order). Whilst in the numerous species of the ancestral genus
_Phractopelta_ all twenty spines remain simple, without such apophyses,
only in a single observed species (representing the genus _Pantopelta_)
were all twenty spines protected by them. In the three other genera only
one part of the spines bears free apophyses, but not the other part. The
most frequent form is _Dorypelta_ (Pl. 133, fig. 2); here eight spines are
simple (four equatorial and four polar spines of the hydrotomical plane),
whilst twelve spines bear apophyses (eight tropical and four polar spines
of the geotomical plane). In _Octopelta_ the eight tropical spines only
bear apophyses, whilst the twelve other (four equatorial and eight polar)
are simple. In _Stauropelta_ finally the four equatorial spines only are
simple, whilst the sixteen other bear free apophyses (eight tropical and
eight polar spines).
_The Central Capsule_ of the Phractopeltida is constantly spherical, and
enclosed between the two concentric spherical shells; it is therefore
larger than the inner and smaller than the outer shell. Its wall is pierced
by the twenty radial beams connecting the two shells. The shape of the
central capsule and of the enveloping calymma is the same as in the other
#Acanthophracta# and specially in the Dorataspida.
_Synopsis of the Genera of Phractopeltida._
{All twenty spines without
{ apophyses in the free
All twenty spines of the { external part, 366. _Phractopelta_.
same form, {
{All twenty spines with
{ apophyses in the free
{ part, 367. _Pantopelta_.
{Eight tropical spines with
{ apophyses, twelve others
{ (eight polar and four
{ equatorial) simple, 368. _Octopelta_.
{
{Twelve radial spines
Twenty radial spines, { (eight tropical and four
partly without, partly { polar) with apophyses,
with apophyses in the { eight others (four polar
free external part, { and four equatorial)
{ simple, 369. _Dorypelta_.
{
{Sixteen radial spines
{ (eight tropical and
{ eight polar) with
{ apophyses, four
{ equatorial, simple, 370. _Stauropelta_.
{852}Genus 366. _Phractopelta_,[406] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Phractopeltida# with twenty simple radial spines, bearing
no free apophyses outside the outer shell.
The genus _Phractopelta_ is the most simple form among the Phractopeltida,
and may be regarded as the common ancestral form of this family. All twenty
spines are of nearly equal form and size, and bear no free apophyses on
their free part, outside the two concentric shells. _Phractopelta_ may be
derived from _Orophaspis_ by further development of the free apophyses,
which by union of their branches form a second outer shell around the
primary shell of that Dorataspid.
Subgenus 1. _Phractopeltaris_, Haeckel.
_Definition._--Outer shell composed of twenty separated plates, the sutures
of their meeting condyles not being grown together.
1. _Phractopelta dorataspis_, n. sp. (Pl. 133, fig. 1).
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with two elliptical
aspinal pores, which are two to three times as broad as the irregular
sutural pores. Radial spines (in the outer free part) compressed, linear,
twice as long as the diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.11, of the inner 0.05.
_Habitat._--North Pacific (off Japan), Station 239, surface.
2. _Phractopelta dyadopora_, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with two kidney-shaped
aspinal pores, which are three to four times as broad as the irregular
sutural pores. Radial spines conical, about as long as the radius of the
shell.
_Dimensions._--Diameter of the outer shell 0.08, of the inner 0.04.
_Habitat._--North Pacific, Station 256, surface.
3. _Phractopelta diporaspis_, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with two quadrangular
aspinal pores, which are four to five times {853}as broad as the irregular
sutural pores. Radial spines compressed, sword-shaped, about as long as the
diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.09, of the inner 0.04.
_Habitat._--South Atlantic, Station 332, surface.
4. _Phractopelta tessaraspis_, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with four crossed,
quadrangular, aspinal pores, the two opposite of which are much larger than
the two others. Sutural pores small, roundish. Radial spines compressed,
linear, about twice as long as the diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.084, of the inner 0.032.
_Habitat._--North Pacific (off Japan), Station 238, surface.
5. _Phractopelta tetradopora_, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with four crossed
quadrangular (or nearly circular) aspinal pores, all of nearly the same
size. Sutural pores polygonal or roundish. Radial spines cylindrical, two
to three times as long as the diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.11, of the inner 0.045.
_Habitat._--North Pacific, Station 253, surface.
6. _Phractopelta hexadopora_, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with six aspinal pores,
the two opposite of which are much larger than the four others. Sutural
pores small, roundish. Radial spines compressed, two-edged, larger than the
diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.04.
_Habitat._--Central Pacific, Station 272, surface.
7. _Phractopelta octadopora_, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are
separated by permanent sutures. Each plate commonly with eight aspinal
pores, the four crossed being larger than the four others alternating with
them. Sutural pores irregular. Radial spines conical, shorter than the
diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.04.
_Habitat._--Indian Ocean (Cocos Islands, surface), Rabbe.
{854}Subgenus 2. _Phractopeltidium_, Haeckel.
_Definition._--Outer shell composed of twenty united plates, the sutures of
their meeting condyles being grown together.
8. _Phractopelta aspidomma_, n. sp.
Outer shell composed of twenty united plates, the meeting condyles of which
are grown together. On the base of each radial spine (where its outer free
part arises from the surface of the outer shell), two large elliptical
aspinal pores, two to four times as large as the other roundish pores.
Radial spines compressed, sword-shaped, about as long as the radius of the
shell.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.05.
_Habitat._--Equatorial Atlantic, Station 347, surface.
9. _Phractopelta haliomma_, n. sp.
Outer shell composed of twenty united plates, the meeting condyles of which
are grown together. On the base of each radial spine two large
kidney-shaped aspinal pores, little larger than the other irregular pores.
Radial spines compressed, linear, two-edged, much longer than the diameter
of the shell.
_Dimensions._--Diameter of the outer shell 0.09, of the inner 0.03.
_Habitat._--South Pacific, Station 295, surface.
10. _Phractopelta tessaromma_, Haeckel.
Outer shell composed of twenty united plates, the meeting condyles of which
are grown together. On the base of each radial spine four crossed
egg-shaped aspinal pores, two opposite of which are much larger than the
two others. Sutural pores irregular. Radial spines cylindrical or little
compressed, thin, longer than the diameter of the shell.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.04.
_Habitat._--Central Pacific, Station 266, surface.
11. _Phractopelta hystrix_, Haeckel.
_Haliomma hystrix_, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 37, Taf. v. figs. 1, 2.
_Aspidomma hystrix_, Haeckel, 1862, Monogr. d. Radiol., p. 424.
Outer shell composed of twenty united plates, the meeting condyles of which
are grown together. On the base of each radial spine four crossed circular
aspinal spines of equal size. Sutural pores roundish, of about the same
size. Radial spines conical, about as long as the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.07, of the inner 0.024.
_Habitat._--Mediterranean (Nice), J. Müller, surface.
{855}Genus 367. _Pantopelta_,[407] n. gen.
_Definition._--#Phractopeltida# with twenty radial spines, each of which is
protected by two free external apophyses.
The genus _Pantopelta_ differs from all other Phractopeltida in the
development of free protecting apophyses on all twenty radial spines. Only
a single specimen of this rare form was seen, and in this all twenty spines
exhibited no marked differences in form and size, but were more or less
irregularly developed.
1. _Pantopelta icosaspis_, n. sp. (Pl. 133, fig. 4).
Apophyses of all twenty radial spines with forked anastomosing branches,
forming a more or less irregular cup-like fenestrated shield, pierced by a
variable number of pores. Distance of the apophyses from the outer shell
equal to half its radius. Pores of the outer shell irregular, roundish,
four to six times as broad as those of the inner shell. Radial spines
compressed, sword-shaped, longer than the radius of the shell.
_Dimensions._--Diameter of the outer shell 0.08, of the inner 0.03.
_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.
Genus 368. _Octopelta_,[408] n. gen.
_Definition._--#Phractopeltida# with twelve simple spines (four equatorial
and eight polar), and with eight tropical spines protected by external free
apophyses.
The genus _Octopelta_ differs from the other Phractopeltida in the
possession of eight shields or pairs of free apophyses outside the outer
lattice-shell; the spines bearing these apophyses are the eight tropical
spines. The twelve other spines (eight polar and four equatorial) are quite
simple, without apophyses.
1. _Octopelta cultella_, n. sp.
Apophyses of the eight tropical spines simple, compressed, knife-shaped,
about as long as their distance from the outer shell. On the base of each
spine (in the network of the outer shell) two orthogonal aspinal pores, two
to three times as long as the other polygonal pores.
_Dimensions._--Diameter of the outer shell 0.08, of the inner 0.03.
_Habitat._--Tropical Atlantic, Station 338, surface.
{856}2. _Octopelta furcella_, n. sp.
Apophyses of the eight tropical spines forked, each with two parallel
simple fork-branches, about as long as their distance from the outer shell.
On the base of each spine (in the outer shell) two kidney-shaped aspinal
pores, about twice as broad as the other irregular pores.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.04.
_Habitat._--South Atlantic (off Tristan d'Acunha), Station 332, surface.
3. _Octopelta scutella_, n. sp. (Pl. 133, fig. 5).
Apophyses of the eight tropical spines crossed by a transverse beam, which
is again crossed by two perpendicular branches; by union of these branches
each tropical spine forms a square shield with four crossed pores and
twelve to sixteen marginal spikes. On the base of each spine (in the
surface of the outer shell) four crossed aspinal pores which correspond to
those of the free shields; these are somewhat larger than the other pores.
_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.06.
_Habitat._--Tropical Atlantic, Station 348, surface.
Genus 369. _Dorypelta_,[409] Haeckel, Prodromus, p. 369.
_Definition._--#Phractopeltida# with eight simple spines (four equatorial
and four hydrotomical polar spines) and with twelve spines protected by
external free apophyses (eight tropical and four geotomical polar spines).
The genus _Dorypelta_, the most common of all Phractopeltida which are
protected by free apophyses, exhibits a very peculiar differentiation of
its twenty radial spines. There are constantly eight simple spines and
twelve spines with apophyses. The eight simple spines are the four
equatorial spines and four polar spines placed in the hydrotomical median
plane. The four other polar spines (placed in the geotomical meridian
plane) and the eight tropical spines are protected by two opposite
apophyses, which are now simple, now branched or shield-shaped. A similar
differentiation occurs in no other Acanthophractida.
Subgenus 1. _Dorypeltarium_, Haeckel.
_Definition._--Free apophyses of the radial spines simple, not branched.
{857}1. _Dorypelta stauroptera_, n. sp.
Apophyses of the long compressed radial spines simple, conical, about as
long as their distance from the shell. At the base of each spine (in the
outer shell) two elliptical aspinal pores, two to three times as large as
the other pores.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.044.
_Habitat._--North Pacific, Station 238, surface.
2. _Dorypelta gladiata_, n. sp.
Apophyses of the long cylindrical radial spines simple, triangular, about
half as long as their distance from the shell. At the base of each spine
(in the outer shell) four crossed aspinal pores, the two opposite of which
are much larger than the other two pores.
_Dimensions._--Diameter of the outer shell 0.09, of the inner 0.04.
_Habitat._--Central Pacific, Station 266, surface.
Subgenus 2. _Dorypeltidium_, Haeckel.
_Definition._--Free apophyses of the radial spines branched, with free (not
anastomosing) branches.
3. _Dorypelta furcata_, n. sp.
Apophyses of the long compressed spines simply forked, each with two simple
parallel fork-branches. At the base of each spine two elliptical aspinal
pores, much larger than the other roundish pores.
_Dimensions._--Diameter of the outer shell 0.08, of the inner 0.04.
_Habitat._--Central Pacific, Station 274, surface.
4. _Dorypelta tetrodon_, n. sp.
Apophyses of the long compressed spines crossed by a transverse beam, which
bears four simple parallel fork-branches or spikes (perpendicular to the
beam), two larger medial and two smaller lateral. At the base of each spine
four crossed aspinal pores of nearly equal size, little different from the
other pores.
_Dimensions._--Diameter of the outer shell 0.09, of the inner 0.035.
_Habitat._--South Pacific, Station 284, surface.
5. _Dorypelta ramosa_, n. sp.
Apophyses of the long cylindrical spines crossed by a transverse beam,
which bears four to six irregularly branched spikes or fork-branches, the
medial of which are larger than the lateral. At {858}the base of each spine
four crossed aspinal pores, two opposite of which are much larger than the
two other pores.
_Dimensions._--Diameter of the outer shell 0.09, of the inner 0.04.
_Habitat._--South Pacific, Station 302, surface.
Subgenus 3. _Dorypeltonium_, Haeckel.
_Definition._--Free apophyses of the radial spines branched, and forming
perforated shields by union of their anastomosing branches.
6. _Dorypelta lithoptera_, n. sp.
Apophyses of the long compressed radial spines with anastomosing branches;
each spine bearing two free separated shields (each with two roundish
aspinal pores). At the base of each spine (in the network of the outer
shell) two elliptical aspinal pores, larger than the other pores.
_Dimensions._--Diameter of the outer shell 0.09, of the inner 0.03.
_Habitat._--North Pacific, Station 239, surface.
7. _Dorypelta tessaraspis_, n. sp. (Pl. 133, fig. 2).
Apophyses of the long cylindrical spines with anastomosing branches; each
spine bearing a single free shield with four crossed aspinal pores of equal
size (on the margin of the shield twelve to sixteen spikes). At the base of
each spine (in the outer shell) four crossed aspinal pores, about as large
as the other roundish pores.
_Dimensions._--Diameter of the outer shell 0.11, of the inner 0.05.
_Habitat._--Central Pacific, Station 263, surface.
8. _Dorypelta dodecaspis_, n. sp.
Apophyses of the long two-edged spines with anastomosing branches; each
spine bearing a single free shield with six to eight parmal pores (four
crossed aspinal pores alternating with four outer coronal pores), on the
margin of each shield twelve to sixteen spikes. At the base of each spine
(in the outer shell) four crossed aspinal pores, about as large as the
other irregular pores.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.04.
_Habitat._--North Pacific (off Japan), Station 235, surface.
Genus 370. _Stauropelta_,[410] Haeckel, 1881, Prodromus, p. 468.
_Definition._--#Phractopeltida# with four simple equatorial spines and
sixteen spines protected by external free apophyses (eight tropical and
eight polar spines).
{859}The genus _Stauropelta_ is distinguished from the other Phractopeltida
by the possession of sixteen pairs of free apophyses (on the eight tropical
and the eight polar spines); only the other four equatorial spines remain
simple, without apophyses, and form a simple cross in the equatorial plane.
1. _Stauropelta cruciata_, n. sp. (Pl. 133, fig. 3).
Apophyses of the long polar and tropical spines crossed by a transverse
beam, which is again crossed by two perpendicular branches parallel to the
apophyses; branches with free ends, not united by concrescence. At the base
of each spine (in the outer shell) two large elliptical aspinal pores,
larger than the other irregular pores. Four equatorial spines simple,
without apophyses, of the same size as the other sixteen spines.
_Dimensions._--Diameter of the outer shell 0.12, of the inner 0.05.
_Habitat._--Indian Ocean (Madagascar), Rabbe, surface.
2. _Stauropelta stauropora_, n. sp.
Apophyses of the long polar and tropical spines crossed by a transverse
beam, which is again crossed by two perpendicular branches parallel to the
apophyses; these branches are united by concrescence, and form a square
shield with four crossed pores, the centre of which is pierced by the
spine. At the base of each spine (in the outer shell) four crossed aspinal
pores, corresponding to those of the shield, of about the same size as the
other roundish pores. Four equatorial spines, simple, without apophyses,
somewhat larger than the other sixteen spines.
_Dimensions._--Diameter of the outer shell 0.1, of the inner 0.04.
_Habitat._--Indian Ocean, Sunda-Archipelago, Singapore, Trebing, surface.
----
Suborder II. PRUNOPHRACTA.
_Definition._--Shell ellipsoidal, lenticular or diploconical, with radial
beams of different size.
Family XLII. #BELONASPIDA#, n. fam. (Pl. 136, figs. 6-9; Pl. 139, figs. 8,
9).
_Definition._--ACANTHARIA with a simple ellipsoidal lattice-shell, composed
of the branched apophyses of twenty radial spines meeting in its centre and
disposed according to the Müllerian law of Icosacantha. Two opposite
equatorial spines larger than the two others. Central capsule ellipsoidal,
enclosed in the fenestrated shell.
The family #Belonaspida#, formerly united by me with the Dorataspida (in
the Prodromus, 1881, p. 468), differs from it in the ellipsoidal form of
the lattice-shell and {860}the enclosed central capsule. In the spherical
Dorataspida, their ancestral family, all twenty radial spines are of equal
size, whilst here in the Belonaspida two opposite spines are larger than
the eighteen others. These two larger or principal spines are both
equatorial spines, placed in the longitudinal or major axis of the
ellipsoid, or the "hydrotomical axis" (compare above, p. 719). The two
other equatorial spines are constantly smaller, and lie in the transverse
or minor axis of the ellipsoid, or the "geotomical axis." The geometrical
proportion of these two determining axes of the ellipsoidal shell is very
variable (even in one and the same species), commonly 4 : 3 or 3 : 2,
rarely 2 : 1, often only 5 : 4 or 6 : 5. All meridian planes, passing
through the principal spines (or the longitudinal axis of the shell) are
elliptical, and of equal size. All transverse planes, perpendicular to that
axis, are circular; the largest of these circular parallel planes is the
geotomical plane, which passes through the smaller equatorial spines and
the spineless axis.
In the spherical Dorataspida the internal length of the radial spines (or
the distance between the shell and the centre) is equal in all twenty
spines. In the ellipsoidal Belonaspida this internal length is different,
and commonly exhibits four different degrees; in the two principal spines
it is of first rank, in the eight tropical spines of second rank, in the
four (hydrotomical) polar spines of third rank, and in the six spines (four
geotomical polar spines and two transverse equatorial spines) of fourth
rank. These differences of the internal length become more important the
more the hydrotomical axis is prolonged. Regarding all other qualities (in
form, disposition, and mode of junction at the centre) the ellipsoidal
Belonaspida do not differ from their ancestral group, the spherical
Dorataspida (compare above, p. 802). In both families the pyramidal central
bases of the twenty spines are commonly supported one upon another with
their triangular neighbouring faces; but sometimes also here (particularly
in _Phatnaspis_) the central bases are perfectly grown together. In this
case also the sutures of the meeting branches of the apophyses are
obliterated, whilst usually they remain open. Such forms, with spines and
plates perfectly grown together, form a single piece of acanthin, and were
formerly separated by me as a peculiar genus _Haliommatidium_ (Monogr. d.
Radiol., 1862, p. 419). But as I now find this concrescence to be an
accidental and inconstant peculiarity of some species, it no longer seems
to me to be of generic importance.
The apophyses of the twenty radial spines, the branches of which compose
the ellipsoidal lattice-shell, exhibit in all Belonaspida the same
appearance as in the Diporaspida (and especially the Ceriaspida) among the
spherical Dorataspida. Everywhere each radial spine gives off only two
opposite primary apophyses, the fork-branches of which unite together and
form a plate or shield with two aspinal pores (as in _Dorataspis_).
Commonly the shell exhibits only these forty parmal pores, the other meshes
between them being sutural pores. Only in one genus, _Phatnaspis_ (Pl. 136,
{861}figs. 6-9), is this number multiplied; the two opposite primary
apophyses are here crossed by numerous perpendicular lateral branches, and
these are again united by secondary perpendicular ramules which are
parallel to the apophyses themselves; therefore each plate here forms a
rhombic shield pierced by very numerous (often more than one hundred) small
quadrangular or circular pores. Only two of these numerous parmal pores are
the primary aspinal pores (sometimes, as in Pl. 136, fig. 8, distinguished
by their larger size); all others are secondary or coronal pores. Therefore
_Phatnaspis_ repeats the characteristic formation of _Coscinaspis_, from
which it differs in its ellipsoidal shell.
Moreover, the four other genera of the ellipsoidal Belonaspida correspond
perfectly to certain genera of the spherical Dorataspida, and may be
derived from these by hypertrophy or stronger development of two opposite
equatorial spines. In _Thoracaspis_ and _Belonaspis_ (Pl. 139, figs. 8, 9)
the surface of the shell-plates is without crests and dimples (in the
former without, in the latter with accessory by-spines); they thus
correspond to _Dorataspis_ and _Diporaspis_ among the Dorataspida. In two
other genera the surface of the shell-plates bears a network of elevated
crests, separating funnel-shaped dimples, in _Dictyaspis_ without, in
_Coleaspis_ with by-spines; these correspond to _Ceriaspis_ and
_Hystrichaspis_ among the Dorataspida. The small by-spines, covering the
surface, exhibit the same forms as in the Dorataspida; but they are usually
smaller, and less developed in the Belonaspida.
The twenty radial spines are commonly more or less compressed or two-edged,
sometimes very flat, broad, and triangular (Pl. 139, figs. 8, 9). In some
species (mainly of _Phatnaspis_) they are very long, thin, and
needle-shaped (Monogr. d. Radiol., 1862, Taf. xxii. figs. 10-12). Rarely
they are cylindrical, four-edged, or prismatic. The Belonaspida testify by
this and other peculiarities to their near relation to the Diporaspida and
Phractacanthida and their older origin from _Zygacantha_.
_The Central Capsule_ is in the Belonaspida ellipsoidal, and more or less
prolonged in the hydrotomical or longitudinal axis of the shell. It is
constantly smaller than the enveloping ellipsoidal shell, and separated
from it by the calymma. Its structure and the shape of its nucleus are the
same as in the nearly allied Dorataspida.
_Synopsis of the Genera of Belonaspida._
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I. Subfamily Coleaspida.
Forty parmal pores (two aspinal pores on each plate, no coronal
pores).
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Plates not dimpled, without { No by-spines, 371. _Thoracaspis_.
prominent crests. {
{ With by-spines, 372. _Belonaspis_.
Plates dimpled, with a { No by-spines, 373. _Dictyaspis_.
network of prominent {
crests, { With by-spines, 374. _Coleaspis_.
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II. Subfamily Phatnaspida.
Eighty to two thousand or more parmal pores (two aspinal pores on
each plate, surrounded by two to one hundred or more coronal pores).
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No by-spines (plates not dimpled), 375. _Phatnaspis_.