Radial tubes with an inflated ovate terminal knob at the distal end, which
bears a variable number of divergent, curved, irregular, terminal branches.
Usually the majority of the tubes bear three branches, whilst others
exhibit two or four, sometimes also five or six. Proximal whorl also very
variable and irregular, with two to six, usually three or four unequal
branches.
_Dimensions._--Length of the tubes 2.0 to 4.0, breadth 0.04 to 0.06;
branches 0.1 to 0.3.
_Habitat._--South Pacific, Station 289, depth 2550 fathoms.
Subgenus 2. _Aulospathilla_, Haeckel.
_Definition._--Distal ends of the radial tubes of equal breadth or tapering
gradually, not inflated, without terminal knobs.
5. _Aulospathis diodon_, n. sp.
Radial tubes without inflated terminal knob, forked at the tapering distal
end, with two divergent curved branches of equal size. Proximal whorl
cruciate, with four rather equal, crossed, straight, lateral branches
(sometimes three or five instead of four in single tubes).
_Dimensions._--Length of the tubes 2.0 to 2.5, breadth 0.03 to 0.04;
branches 0.1 to 0.3.
_Habitat._--North Pacific, Station 231, depth 2250 fathoms.
6. _Aulospathis triodon_, n. sp. (Pl. 104, fig. 8).
Radial tubes without inflated terminal knob, with three divergent, slightly
curved, terminal branches. Proximal whorl with a variable number of curved
lateral branches, usually also three (often two or four, rarely more).
_Dimensions._--Length of the tubes 2 to 3, breadth 0.03 to 0.05; branches
0.2 to 0.3.
_Habitat._--North Pacific, Stations 250 to 253, depth 2740 to 3125 fathoms.
{1588}7. _Aulospathis tetrodon_, n. sp. (Pl. 104, fig. 9).
Radial tubes without inflated terminal knob, with four crossed, divergent,
slightly curved terminal branches. Proximal whorl usually with an irregular
cross of four lateral branches (often five or six, rarely two or three
instead of the usual four).
_Dimensions._--Length of the tubes 2.0 to 2.5, breadth 0.03 to 0.04;
branches 0.2 to 0.3.
_Habitat._--North Pacific, Stations 244 to 245, depth 2775 to 2900 fathoms.
8. _Aulospathis hexodon_, n. sp.
Radial tubes without inflated terminal knob, with three forked, curved
branches at the distal end, so that each tube usually bears six terminal
branches; but other tubes of the same specimen bear only three simple or a
few irregularly forked branches. Proximal whorl usually with six curved,
irregular, lateral branches.
_Dimensions._--Length of the tubes 2.0 to 3.0, breadth 0.03 to 0.06;
branches 0.2 to 0.5.
_Habitat._--Western Tropical Pacific, Station 224, depth 1850 fathoms.
9. _Aulospathis furcata_, n. sp.
Radial tubes without inflated terminal knob, with a variable number of
unequal terminal branches, which are partly simple, partly irregularly
forked or branched; the usual number of terminal branches is three or four,
more rarely two or five or six. Proximal whorl very irregular, usually with
four to six unequal, lateral branches.
_Dimensions._--Length of the tubes 2.0 to 2.5, breadth 0.03 to 0.05;
branches 0.1 to 0.3.
_Habitat._--Stations 265 to 268, depth 2700 to 2900 fathoms.
10. _Aulospathis variabilis_, n. sp. (Pl. 104, figs. 14-17).
Radial tubes without inflated terminal knob, with a variable number of
unequal terminal branches, which are constantly simple, never forked; the
usual number is in the majority of the tubes three or four, often also two,
rarely five to eight. Proximal whorl irregular, with a variable number of
lateral branches (usually four to six).
_Dimensions._--Length of the tubes 2.0 to 3.0, breadth 0.03 to 0.06;
branches 0.1 to 0.3.
_Habitat._--Central Pacific, Stations 271 to 274, depth 2350 to 2750
fathoms.
Genus 670. _Aulodendron_,[288] n. gen.
_Definition._--#Aulacanthida# with a veil of tangential needles, and with
radial tubes, which bear numerous, irregularly scattered, lateral and
terminal branches.
{1589}The genus _Aulodendron_ differs from the other Aulacanthida in the
possession of lateral and terminal branches, which are irregularly
scattered on the radial tubes and not arranged in regular verticils. The
branches are usually short, simple or forked, rarely longer and again
irregularly ramified.
1. _Aulodendron antarcticum_, n. sp. (Pl. 105, fig. 5).
Radial tubes cylindrical, more or less curved, in the inner proximal half
smooth and half as broad as in the outer distal half, which is studded with
irregularly curved, partly branched spines, arising usually perpendicularly
from the tube. The majority of the spines usually simple, the minority
forked, with two to four short branches, the largest spines scarcely twice
as long as the breadth of the tube.
_Dimensions._--Length of the tubes 0.7 to 0.9, breadth 0.01 to 0.02; length
of the branches 0.02 to 0.04.
_Habitat._--Antarctic Ocean (Kerguelen), Stations 156 to 159, surface.
2. _Aulodendron pacificum_, n. sp. (Pl. 105, fig. 2).
Radial tubes cylindrical, slightly curved, in the proximal half smooth, in
the distal half with scattered lateral branches, which are partly simple,
partly forked, about twice as long as the breadth of the tube, and bear at
the distal end a spathilla with five to six recurved teeth. The distal end
of the tubes bears a spherical knob, which is separated by a deep stricture
and armed with a bunch of six to twelve strong conical teeth.
_Dimensions._--Length of the tubes 1 to 1.2, breadth 0.015 to 0.02;
branches 0.03 to 0.04.
_Habitat._--South Pacific, Station 293, depth 2025 fathoms.
3. _Aulodendron australe_, n. sp. (Pl. 105, fig. 3).
Radial tubes cylindrical, straight, thin, smooth in the proximal half,
armed with numerous lateral branches in the distal half; the majority of
the branches forked, about as long as the breadth of the tube, with two or
three short ramules, each of which bears a spinulate terminal knob. The
distal end of the tubes also forked, with two or three divergent branches.
_Dimensions._--Length of the tubes 1.2 to 1.6, breadth 0.01 to 0.012.
_Habitat._--South Pacific, Station 289; New Zealand, Station 169, surface.
4. _Aulodendron atlanticum_, n. sp.
Radial tubes cylindrical, tapering gradually towards the two ends; smooth
and straight in the proximal half, irregularly curved and branched in the
distal half, with ten to twenty (rarely more) branches, which arise almost
perpendicularly from the tube. The proximal branches are from four to eight
times as long as the greatest breadth of the tube, forked, with two or
three short ramules; {1590}the distal branches are much smaller and simple.
The distal end of each branch bears a spathilla with four to six short
teeth.
_Dimensions._--Length of the tubes 2.4 to 3.6, breadth 0.06 to 0.08.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
5. _Aulodendron indicum_, n. sp. (Pl. 105, fig. 1).
Radial tubes cylindrical, irregularly curved, tapering gradually towards
the two ends; smooth in the proximal half, irregularly branched in the
distal half, with ten to twenty or more curved branches. The proximal
branches are very large, one-sixth to one-fourth as long as the tube and
irregularly ramified; the distal branches are much shorter, also ramified
or simple. All the branches are more or less curved and bear a spinulate
knob at the distal end.
_Dimensions._--Length of the tubes 1.2 to 1.8, breadth 0.02 to 0.03; length
of the branches 0.1 to 0.3.
_Habitat._--Indian Ocean; Cocos Islands (Rabbe), surface.
----
Order II. PHÆOSPHÆRIA, Haeckel, 1879.
_Definition._--PHÆODARIA with a simple or double, usually spherical
lattice-shell, which is not bivalved and has no peculiar mouth or
peristome. Central capsule placed in the centre of the shell.
Family LXXIV. #OROSPHÆRIDA#, n. fam. (Pls. 106, 107).
_Definition._--PHÆODARIA with a big spherical (sometimes polyhedral or
ellipsoidal), very coarse shell, which is composed of thick bars containing
an axial canal. Nodal points of the coarse network without astral septa.
Meshes of moderate size, irregularly polygonal. Surface of the shell
usually with radial spines and pyramidal elevations. No peculiar mouth in
the shell. Central capsule tripylean, in the centre of the shell.
The family #Orosphærida# comprises those PHÆODARIA which possess a simple
spherical or polyhedral lattice-shell, composed of hollow, very thick,
non-articulate rods, without a peculiar shell-mouth. They agree in the
considerable size of the spherical lattice-shell and the absence of a
peculiar shell-mouth with the other #Phæosphæria#, but differ from them in
the coarse and irregular shape of the massive network, which is composed of
irregular polygonal meshes, separated by very thick concentrically
stratified rods, containing a fine axial canal. The closely allied
Sagosphærida differ from them in the delicate shape of the solid and very
thin, filiform rods of the network, and its subregular {1591}triangular
meshes. The Aulosphærida differ in the development of the peculiar nodal
cavities and astral septa, by which the thin-walled cylindrical tubes of
the articulated network are separated in the stellate nodal points. The
Cannosphærida, closely allied to these latter, also differ in the
articulated network, and further in the possession of an internal
concentric shell. The Castanellida are sometimes similar to the
Orosphærida, but distinguished by a peculiar large shell-mouth and a
network of different shape.
The Orosphærida belong to the biggest Radiolaria, and the lattice-work of
their spherical shell is of a ruder and coarser shape than in any of the
other families of this class. Nevertheless they have been hitherto
perfectly unknown, and were first discovered by the Challenger. We have
been able to distinguish in the collection four genera and twenty-seven
species. This strange fact may be explained by the circumstance, that they
are in general rare, and restricted to a few localities, and that probably
all the species are inhabitants of great depths. Complete shells also are
rarely found, whilst broken fragments of their big shells, easily
recognisable by the coarse irregular meshes and the thick stratified bars,
are met with frequently in the Radiolarian ooze of some Pacific Stations,
especially at Stations 265 and 268, at a depth of 2900 fathoms.
The lattice-shell of the Orosphærida is usually spherical, or an
endospherical polyhedron (Pl. 106, fig. 4); rarely one axis is somewhat
prolonged, so that the shell becomes slightly ellipsoidal (Pl. 106, fig.
1). Its diameter is usually between 2 and 3, often also between 2 and 1
mm., rarely more than 3, or less than 1 mm. The largest shells observed
attained 5 to 6, the smallest 0.5 to 0.6 mm. Their general habit is very
characteristic, so that they may be easily distinguished from all other
spherical lattice-shells, especially from the Castanellida and from the
simple Monosphærida (_Cenosphæra_, _Acanthosphæra_), with which I
confounded them in the beginning (hence the first shell observed, figured
in 1878, was placed among the Monosphærida in Pl. 12). A closer examination
of the coarse network and of the peculiar structure of its thick bars
always enables one to recognise even small isolated fragments of broken
shells.
The meshes of the coarse network exhibit in all observed Orosphærida a very
irregular form and unequal size; the majority are usually more or less
quadrangular, more rarely they are triangular, pentagonal or hexagonal,
very rarely rounded. They are often arranged in parallel rows, which seem
to be determined by prominent crests, connecting the bases of the radial
spines (Pl. 12, fig. 1; Pl. 106, fig. 4, &c.). The diameter of the meshes
is usually between 0.05 and 0.1, often 0.1 to 0.2, rarely more than 0.25,
or less than 0.025 mm. In _Oroplegma_, which develops an outer loose,
spongy shell around the inner primary shell, the big meshes of the former
become much larger and very irregular (Pl. 107, fig. 1).
The coarse bars which separate the large meshes of the irregular network
are very thick and massive, cylindrical, usually of unequal thickness,
straight or slightly curved, never angular or prismatic. Their diameter is
usually between 0.01 and 0.02, rarely {1592}more than 0.03 or less than
0.005 mm. Their surface is either smooth or slightly spinulate. Examined in
the dry state and by strong lenses, they constantly exhibit a fine, but
distinct longitudinal striation, as the expression of concentric
stratification. A fine axial canal or central tubule is usually visible in
the axis of each rod, and often this axial canal is studded with numerous
short lateral branches (Pl. 107, figs. 2, 4, 8). But very often the axial
canals become rudimentary or lost, or are developed only in a part of the
bars (Pl. 12, fig. 1). When they are completely developed, the entire
network of the shell is drained by a reticulate system of communicating
axial canals; they are probably filled by jelly in the living body. This
tubular system never attains that regularity and high development which is
constantly found in the Aulosphærida; and the characteristic stellate nodal
points of the latter, with their astral septa, are never found in any of
the Orosphærida. Moreover the wall of the tubular bars is very thin and
structureless in the Aulosphærida, very thick and stratified in the
Orosphærida, the enclosed canal very wide in the former, very narrow in the
latter. The stratification of the concentric cylindrical lamellæ, which
surround the narrow axial canal, is effected by the gradual deposition of
the concentric layers, and is very similar to that which is found in the
thick spicula of many sponges. The peculiar structure of the bars in the
Orosphærida becomes very distinct if the skeleton be burned, or acted upon
by fire for some time; it then assumes a brown colour and its surface often
appears dimpled. Sometimes the concave dimples on the surface of the bars
are rather deep and separated by prominent crests (Pl. 107, figs. 4, 7).
The few genera of Orosphærida which are here distinguished have all the
same structure, are closely allied, and differ mainly in the shape of the
outer surface of the lattice-sphere. The latter is quite simple and smooth
only in _Orona_. In the common _Orosphæra_ (Pl. 106, figs. 1-3) it is
studded with radial spines. In the most frequent form, _Oroscena_, the
shell has a pyramidal or tent-shaped elevation on the base of each radial
spine, and usually the bases of the neighbouring spines are connected by
strong prominent crests, the edges of the three-sided or four-sided
pyramids (Pl. 12, fig. 1; Pl. 106, fig. 4). This remarkable form is more or
less polyhedral, with concave sides, and is similar to the characteristic
shells which are represented by _Auloscena_ among the Aulosphærida, by
_Sagoscena_ and _Sagoplegma_ among the Sagosphærida (compare Pls. 108 and
110). The pyramids or tents, however, are in these latter more regularly
and distinctly developed than in the Orosphærida. The radial spines which
arise form the top of the pyramids are often branched, and the branches
become connected to form an outer enveloping secondary shell or a loose
spongy framework in _Oroplegma_ (Pl. 107, fig. 1).
The radial spines of the Orosphærida never exhibit a constant number or
disposition in the individual species; their usual number is from twenty to
sixty. Their form exhibits two different types, which, however, are not
sharply separated; robust club-shaped and slender rod-shaped spines. The
robust club-shaped spines are usually about as long as {1593}the diameter
of the shell; they are longitudinally striped in the basal part, spinulate
or reticulately dimpled in the distal part; sometimes they are straight, at
other times curved or undulate (Pl. 106, figs. 1-4; Pl. 107, figs. 4-6).
The slender rod-shaped spines are usually longer than the diameter of the
shell, cylindrical, more or less curved or even undulate, smooth or thorny,
sometimes irregularly branched, and often the branches are all or partly
connected (Pl. 106, fig. 3; Pl. 107, fig. 1). In the majority of the shells
observed the radial spines were found to be partly broken off. Their
structure is the same as that of the bars of the network; but the central
axial canal and the surrounding concentric lamellæ are usually more
distinct than in the latter.
The central capsule of the Orosphærida lies in the centre of the spherical
lattice-shell, surrounded by the voluminous calymma, which fills up its
cavity. The form, structure, and size of the central capsule are the same
as in the closely allied Aulosphærida (Pl. 111, fig. 2). Its diameter is
usually about 0.2, or between 0.15 and 0.25, rarely more than 0.3 or less
than 0.12. The dark phæodium is of about the same volume as the central
capsule, and envelops its oral half with the radiate operculum and the
proboscis of the astropyle. The two opposite parapylæ are small.
_Synopsis of the Genera of Orosphærida._
I. Subfamily { Surface smooth, without
Oronida. { radial spines, 671. _Orona_.
Surface of the shell {
without pyramidal { Surface studded with simple or
or tent-shaped { branched radial spines, 672. _Orosphæra_.
elevations. {
II. Subfamily { Pyramids of the surface free,
Oroscenida. { without spongy envelope, 673. _Oroscena_.
Surface of the shell {
with numerous { Pyramids of the surface
pyramidal or tent- { connected by a spongy
shaped elevations. { envelope or an external
{ lattice-shell, 674. _Oroplegma_.
Genus 671. _Orona_,[289] n. gen.
_Definition._--#Orosphærida# with a simple spherical or slightly
ellipsoidal shell, without pyramidal elevations and radial spines.
The genus _Orona_ is the simplest of the Orosphærida, and probably the
common ancestral form of this family. The lattice-shell is a simple
fenestrated sphere, sometimes slightly ellipsoidal, with prolonged main
axis, and bears on its surface neither tent-shaped elevations nor radial
spines. It may be confounded with some big forms of _Cenosphæra_; it
differs, however, in the possession of hollow central canals in the thick
bars of the very coarse lattice-plate.
{1594}1. _Orona maxima_, n. sp. (Pl. 107, fig. 5).
Shell spherical, with very irregular polygonal meshes. Bars of the loose
network smooth or slightly spinulate, very thick, with a pinnulate axial
canal.
_Dimensions._--Diameter of the sphere 5.0 to 5.5, of the meshes 0.2 to 0.4,
of the bars 0.01.
_Habitat._--Central Pacific, Station 265, depth 2900.
2. _Orona robusta_, n. sp.
Shell spherical, with irregular quadrangular meshes (intermingled with
single triangular, pentagonal, and hexagonal meshes). Bars of the coarse
network very thick, spinulate.
_Dimensions._--Diameter of the sphere 3.0 to 3.6, of the meshes 0.05, of
the bars 0.012.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
3. _Orona crassissima_, n. sp. (Pl. 107, fig. 7).
Shell ellipsoidal, slightly prolonged in the main axis, with irregular
polygonal meshes of very different sizes and unequal forms. Bars of the
coarse network very thick, thorny and dimpled, their surface being covered
with a network of prominent polygonal crests.
_Dimensions._--Diameter of the sphere 3.0 to 4.0, of the meshes 0.2 to 0.5,
of the bars 0.02 to 0.06.
_Habitat._--South Pacific, Station 289, depth 2550 fathoms.
Genus 672. _Orosphæra_,[290] n. gen.
_Definition._--#Orosphærida# with a simple, spherical (sometimes slightly
ellipsoidal or polyhedral) lattice-shell without pyramidal elevations, but
with numerous radial spines.
The genus _Orosphæra_ differs from the preceding _Orona_, its ancestral
form, in the development of simple or branched radial spines. It bears,
therefore, the same relation to the latter that _Acanthosphæra_ has to
_Cenosphæra_. In the two latter genera, however, the bars of the network
are solid, in the two former hollow. The species referred to _Orosphæra_
are closely allied and require a further accurate examination.
Subgenus 1. _Oronium_, Haeckel.
_Definition._--Radial spines simple, smooth or spiny, but neither branched
nor arborescent.
{1595}1. _Orosphæra hastigera_, n. sp.
Radial spines cylindrical, straight, smooth, simple, about as long as the
diameter of the spherical shell, and as broad as its smooth bars. Meshes of
the network irregularly polygonal, the majority quadrangular, of different
sizes.
_Dimensions._--Diameter of the sphere 1.0 to 1.2, length of the radial
spines 1.1 to 1.5, middle breadth 0.004.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
2. _Orosphæra spinigera_, n. sp.
Radial spines cylindrical, irregularly curved, thorny, simple, two to three
times as long as the diameter of the spherical shell, and as broad as its
spiny bars. Meshes of the network irregularly polygonal, the majority
pentagonal.
_Dimensions._--Diameter of the sphere 1.5 to 1.8, length of the spines 3.0
to 5.0, breadth 0.006.
_Habitat._--North Atlantic, Station 353, depth 2965 fathoms.
3. _Orosphæra fusigera_, n. sp.
Radial spines slender, spindle-shaped, straight, smooth, about as long as
the diameter of the spherical or slightly ellipsoidal shell, in the thicker
middle part five times as broad as the bars, and tapering equally towards
both ends. Meshes of the network irregularly polygonal, the majority
quadrangular, separated by smooth bars.
_Dimensions._--Diameter of the shell 1.0 to 1.2, length of the spines 1.2
to 1.6, basal breadth 0.02, middle breadth 0.1.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
4. _Orosphæra foveolata_, n. sp.
Radial spines spindle-shaped, straight, dimpled, half as long as the radius
of the spherical shell and three to five times as thick as the bars. Meshes
irregular, polygonal, of very different shapes, separated by dimpled bars.
(Similar to _Oroscena gegenbauri_, Pl. 106, fig. 4, but with spherical
dimpled shell, without pyramidal elevations.)
_Dimensions._--Diameter of the shell 2.0 to 2.4, length of the spines 0.5,
breadth 0.15.
_Habitat._--Central Pacific, Station 267, depth 2700 fathoms.
5. _Orosphæra serpentina_, n. sp. (Pl. 106, fig. 1).
Radial spines cylindrical, dimpled, undulate or curved in a snake-like
manner, about as long as the diameter of the ellipsoidal or spherical shell
and four to six times as broad as its smooth bars. Meshes very irregular,
polygonal.
_Dimensions._--Diameter of the shell 1.0 to 1.2, length of the spines 0.12
to 0.15, breadth 0.12.
_Habitat._--South Pacific, Station 289, depth 2550 fathoms.
{1596}6. _Orosphæra horrida_, n. sp. (Pl. 106, fig. 2).
Radial spines club-shaped, very strong, straight, about as long as the
diameter of the polyhedral shell, ovate and smooth in the distal half,
slenderly conical, and armed with recurved spines in the proximal half;
their outer third is the thickest, and five times as broad as the smooth
bars of the coarse network. Meshes of the latter irregularly quadrangular.
_Dimensions._--Diameter of the shell 1.2 to 1.6, length of the spines 1.2
to 2.0, breadth 0.2.
_Habitat._--South Pacific, Station 291, depth 2250 fathoms.
7. _Orosphæra clavigera_, n. sp.
Radial spines club-shaped, thickened towards the distal end, more or less
curved, spinulate, about as long as the diameter of the spherical shell; in
the distal third four to six times as broad as the spinulate bars. Meshes
irregularly polygonal, the majority pentagonal.
_Dimensions._--Diameter of the shell 2.0 to 2.5, length of the spines 1.8
to 2.2, breadth 0.16.
_Habitat._--Central Pacific, Station 263, depth 2650 fathoms.
Subgenus 2. _Orothamnus_, Haeckel.
_Definition._--Radial spines branched or arborescent.
8. _Orosphæra ramigera_, n. sp.
Radial spines cylindrical, spinulate, straight, about twice as long as the
diameter of the spherical shell and as thick as its spinulate bars.
Numerous simple spinulate branches, straight or slightly curved, and two to
four times as long as the meshes, are irregularly scattered, and arise
nearly perpendicularly from the bars.
_Dimensions._--Diameter of the shell 2.0 to 2.2, length of the spines 4 to
5, breadth 0.05.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
9. _Orosphæra furcata_, n. sp.
Radial spines cylindrical, smooth, irregularly curved, about as long as the
radius of the spherical shell and as thick as its smooth bars, forked at
the distal end, with two or three terminal branches of various lengths.
Meshes irregularly polygonal (the majority hexagonal).
_Dimensions._--Diameter of the shell 1.2, length of the spines 0.7, breadth
0.03.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface (?).
10. _Orosphæra confluens_, n. sp.
Radial spines cylindrical, smooth, irregularly curved, two to three times
as long as the diameter of the polyhedral shell, twice as broad as its
smooth bars, bearing numerous irregular, lateral {1597}branches, which are
partly confluent and fenestrated (similarly as in Pl. 107, fig. 1), but not
forming an outer lattice-shell. Meshes irregularly polygonal.
_Dimensions._--Diameter of the shell 3.3, length of the spines 6 to 9,
breadth 0.03.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.
11. _Orosphæra arborescens_, n. sp. (Pl. 106, fig. 3).
_Orothamnus arborescens_, Haeckel, 1881, Atlas, loc. cit.
Radial spines cylindrical, rough, more or less curved, somewhat longer than
the diameter of the subspherical or slightly ellipsoidal shell, and at the
thicker base three times as broad as its smooth bars, bearing numerous
irregularly branched and curved, sometimes confluent, lateral branches.
Meshes irregularly quadrangular.
_Dimensions._--Diameter of the shell 1.2 to 1.6, length of the spines 1.5
to 2.2, breadth 0.06.
_Habitat._--South Atlantic, Station 335, depth 1425 fathoms.
Genus 673. _Oroscena_,[291] n. gen.
_Definition._--#Orosphærida# with a simple, polyhedral or subspherical
lattice-shell, and with numerous pyramidal elevations on its surface, the
top of which bears a radial spine.
The genus _Oroscena_ differs from the preceding _Orosphæra_ in the
possession of numerous pyramidal or tent-shaped elevations, each of which
bears on its top a radial spine. It exhibits therefore the same relation to
the latter that _Sagoscena_ does to _Sagosphæra_ and _Auloscena_ to
_Aulosphæra_. The bases of the radial spines are usually connected by
prominent concave crests, the edges of the pyramids. The species described
of _Oroscena_ seem to be very variable and transformistic.
Subgenus 1. _Oroscenium_, Haeckel.
_Definition._--Radial spines simple, smooth or spiny, but neither branched
nor forked.
1. _Oroscena gegenbauri_, n. sp. (Pl. 106, fig. 4).
Radial spines club-shaped, about half as long as the radius of the shell,
cylindrical and finely sulcate in the basal third, ovate and elegantly
dimpled in the distal two-thirds. The bases of the radial spines are
connected by prominent concave crests, which form the edges of the
polyhedral shell. Meshes irregularly polygonal, the majority quadrangular,
separated by denticulate bars.
{1598}_Dimensions._--Diameter of the shell (without spines) 1.2 to 1.8, of
the meshes 0.04 to 0.1; length of the spines 0.3 to 0.5.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
2. _Oroscena mülleri_, n. sp. (Pl. 107, fig. 8).[292]
Radial spines club-shaped, very similar to that of the preceding species,
but much larger, about as long as the radius of the shell. Meshes
irregularly polygonal, the majority pentagonal, separated by smooth bars.
_Dimensions._--Diameter of the shell 2.0 to 2.4, length of the spines 1.0
to 1.2.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
3. _Oroscena cuvieri_, n. sp. (Pl. 107, fig. 6).
Radial spines club-shaped, compressed and smooth in the proximal half,
spindle-shaped and dimpled in the distal half, about as long as the radius
of the shell. Meshes irregularly polygonal, the majority hexagonal,
separated by denticulate bars.
_Dimensions._--Diameter of the shell 1.5, length of the spines 0.8.
_Habitat._--South Pacific, Station 289, depth 2550 fathoms.
4. _Oroscena bærii_, n. sp. (Pl. 107, fig. 4).
Radial spines nearly spindle-shaped, undulate, tapering from the thicker
middle towards both ends, coarsely dimpled, about one-third as long as the
radius of the shell. Meshes irregularly polygonal, the majority pentagonal,
separated by spinulate bars.
_Dimensions._--Diameter of the shell 3.2, length of the spines 1.0 to 1.2,
breadth 0.1.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
5. _Oroscena wolffii_, n. sp.
Radial spines cylindrical, spinulate, more or less curved, longer than the
diameter of the shell and about twice as broad as its bars. Meshes
irregularly polygonal, of very variable form and unequal size, separated by
smooth bars.
_Dimensions._--Diameter of the shell 2.5, length of the spines 3.0 to 3.5,
breadth 0.02.
_Habitat._--Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms.
Subgenus 2. _Orodendrum_, Haeckel.
_Definition._--Radial spines branched or arborescent.
{1599}6. _Oroscena huxleyi_, n. sp. (Pl. 12, figs. 1, 1_a_).
Radial spines cylindrical, obliquely ascending and irregularly curved,
about as long as the diameter of the shell and somewhat thicker than its
thorny bars. A variable number of short, irregular, partly simple, partly
forked, lateral branches arises from the spines. Meshes of the network very
irregular, partly solid, partly hollow (fig. 1_a_*), the majority
quadrangular. This species, the first observed form of Orosphærida
(captured the 21st February 1873 at Station 5), was at the beginning of my
observations, in 1876, and when I had no knowledge of the central capsule,
erroneously regarded by me as a gigantic Sphæroid (of the Monosphærida) and
therefore placed in Pl. 12. The long branched spines, afterwards observed
complete in another specimen, were broken off in the specimen first
figured.
_Dimensions._--Diameter of the shell 2.0 to 2.5, length of the spines 2 to
3 mm., breadth 0.03.
_Habitat._--North Atlantic (west of Canary Islands), Station 5, depth 2740
fathoms.
7. _Oroscena darwinii_, n. sp.
Radial spines cylindrical, irregularly curved and branched, about twice as
long as the diameter of the shell; the branches are all again ramified and
partly confluent (as in Pl. 107, fig. 1). The branches and the bars of the
network are of equal breadth, smooth (not thorny as in the similar
preceding species). Meshes rather subregular, quadrangular.
_Dimensions._--Diameter of the shell 2.4 to 2.8, length of the spines 4 to
5 mm., breadth 0.015.
_Habitat._--Tropical Atlantic, Station 348, depth 2450 fathoms.
8. _Oroscena duncanii_, n. sp.
? _Hexactinellida dictyonina_, Martin Duncan, 1881, Journ. Roy. Micr.
Soc., p. 175, pl. iii. figs. 4, 6.
Radial spines cylindrical, thorny, arborescent, somewhat shorter than the
diameter of the shell, with irregular ramified branches (similar to
_Orosphæra arborescens_, Pl. 106, fig. 3). The size and ramification of the
arborescent spinulate branches decrease towards the apex. The thicker
branches are from two to three times as broad as the spinulate bars of the
network. Meshes of the latter irregular, the majority quadrangular.
_Dimensions._--Diameter of the shell 3.2, length of the spines 3.5 to 4.5,
breadth 0.02 to 0.3.
_Habitat._--South Atlantic, Station 318, depth 2040 fathoms; coast of
Portugal, 1095 fathoms.
Genus 674. _Oroplegma_,[293] n. gen.
_Definition._--#Orosphærida# with a spongy, spherical or slightly
polyhedral lattice-shell, which is enveloped by a loose spongy framework
and bears numerous radial spines.
The genus _Oroplegma_ differs from the other Orosphærida in the development
of an external lattice-work enveloping the internal primary shell, and
produced by the union {1600}of the branches of the radial spines. This
outer shell is either a simple lattice-plate (comparable to the cortical
shell of _Diplosphæra_), or a spongy framework (as in _Rhizoplegma_).
Subgenus 1. _Oroplegmium_, Haeckel.
_Definition._--External shell a simple fenestrated lamella, forming an
outer concentric lattice-sphere around the inner primary shell.
1. _Oroplegma diplosphæra_, n. sp. (Pl. 107, fig. 1).
Radial spines slender, cylindrical, smooth, more or less curved, about
twice as broad as the smooth bars of the network. External shell a simple
irregular lattice-sphere, with loose polygonal meshes, which are on an
average three to four times as broad as the irregular meshes of the
internal shell. The free prominent parts of the radial spines are
irregularly branched, very long, with partly confluent branches.
_Dimensions._--Diameter of the inner sphere 1.5 to 2.0, of the outer 2.5 to
3.0; length of the free spines 1.2, breadth 0.04.
_Habitat._--Central Pacific, Station 265, depth 2900 fathoms.
2. _Oroplegma spinulosum_, n. sp.
Radial spines slender, cylindrical, thorny, more or less curved, very
similar to those of the preceding species; the shell also much resembles
that of _Oroplegma perplexum_. It differs from the latter in the more
regular fenestration of both shells, and mainly in the shape of the bars
and the spine-branches, which are all spinulate and densely studded with
small conical thorns.
_Dimensions._--Diameter of the inner sphere 1.5 to 2.0, of the outer 2.5 to
3.0; length of the spines 1.2, breadth 0.03.
_Habitat._--Central Pacific, Station 268, depth 2900 fathoms.
3. _Oroplegma velatum_, n. sp.
Radial spines stout, cylindrical, somewhat club-shaped, spiny, slightly
curved, about three to four times as broad as the thorny bars of the
network. External shell a simple lattice-sphere with irregular polygonal
meshes, which are for the most part pentagonal and about four times as
broad as the polygonal meshes of the inner shell. The free prominent parts
of the radial spines are thickened, club-shaped, and about as long as the
radius.
_Dimensions._--Diameter of the inner sphere 2.0 to 2.4, of the outer 2.8 to
3.6; length of the free spines 0.5 to 0.7, breadth 0.12 to 0.15.
_Habitat._--Tropical Atlantic, Station 338, depth 1990 fathoms.
{1601}Subgenus 2. _Orodictyum_, Haeckel.
_Definition._--External shell a complex framework, forming an outer spongy
envelope around the inner primary shell.
4. _Oroplegma spongiosum_, n. sp. (Pl. 107, fig. 3).
Radial spines stout, cylindrical, spinulate, slightly curved, three to five
times as broad as the inner rough bars. External shell with pyramidal
elevations, forming a loose spongy framework, the irregular polygonal
meshes of which are two to five times as broad as those of the enclosed
internal shell; the thickness of the spongy envelope equals about half the
radius of the inner shell. External free prolongations of the radial spines
about equal to the radius.
_Dimensions._--Diameter of the inner sphere 2 to 2.5, of the outer 3 to
3.5; length of the free radial spines 0.5 to 2.0, breadth 0.1.
_Habitat._--North Pacific, Station 241, depth 2300 fathoms.
5. _Oroplegma giganteum_, n. sp. (Pl. 107, fig. 2).
Radial spines slender, cylindrical, spinulate, irregularly curved, about
twice as broad as the spinulate tubular bars of the network (fig. 2).
External shell an irregular, loose, spongy framework, the polygonal meshes
of which are three to six times as broad as the rounded irregular meshes of
the inner shell; the thickness of the spongy envelope about equals the
radius of the inner shell. External free prolongation of the radial spines
irregularly branched.
_Dimensions._--Diameter of the inner sphere 3.2 to 3.5, of the outer 5.4 to
6.6; length of the free spines 1.4 to 1.5, breadth 0.03.
_Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms.
Family LXXV. #SAGOSPHÆRIDA#, n. fam. (Pl. 108).
_Definition._--PHÆODARIA with a large spherical (or sometimes polyhedral),
very delicate shell, which is composed of solid, very thin and long
threads. Nodal points of the arachnoidal network without astral septa.
Meshes large, triangular. Surface of the shell usually armed with radial
spines and often studded with pyramidal elevations. No peculiar mouth in
the shell. Central capsule tripylean, in the centre of the shell.
The family #Sagosphærida# comprises a rather large number of common and
widely distributed PHÆODARIA, which in respect of the special form and
differentiation of the shell exhibit the greatest similarity to the common
Aulosphærida, but differ essentially from them in the peculiar structure of
the network. This is not composed of stout hollow cylindrical tubes, but of
solid, very thin threads; and these fine arachnoidal {1602}threads are
simply united or confluent at the nodal points, and are not connected by a
radial or stellate septal junction, as in the Aulosphærida. There are,
therefore, neither astral septa nor a nodal cavity in each nodal point. The
delicate shape of the thin and fragile threads separates the Sagosphærida
from the closely allied Orosphærida, the thick bars of which contain a
central axial canal and exhibit a concentric structure. Another difference
between these two similar families is indicated by the form of the meshes
of the network, which are constantly triangular in the Sagosphærida, but
irregularly polygonal or quadrangular in the Orosphærida. The general habit
of these two families, however, is very different, since the big and stout
spheres of the Orosphærida are the coarsest and rudest spherical shells of
all Radiolaria, whilst the fragile and delicate spheres of the Sagosphærida
represent the finest and most tender in the whole class.
The spherical lattice-shell of the Sagosphærida has a considerable size,
its diameter being usually between one and three millimetres, rarely less
or more. Some species are very common and widely distributed, usually
accompanying the common Aulosphærida; very frequently the similar shells of
the two are found interwoven. But in spite of this frequency and visible
size, the Sagosphærida have hitherto almost completely escaped the
attention of observers. The main cause of this strange fact may be their
extreme delicacy and fragibility, so that complete and intact shells occur
very rarely, the majority being more or less broken and incomplete. It
seems that only two species of Sagosphærida have been hitherto observed.
The first form described is _Sagmarium trigonizon_, observed by me in 1859
living at Messina, and figured in 1862 in my Monograph as _Dictyosoma
trigonizon_ (Taf. xxvi. figs. 4-6), but afterwards called _Spongodictyum
trigonizon_ (_loc. cit._, p. 459). I supposed at that time (now twenty-five
years ago), that this remarkable and in many respects distinct form might
belong to the Spongosphærida, and that an internal, triple, spherical
lattice-shell, found entangled in its spongy framework, might be its
central "medullary shell." But at present, having found many shells of
different Radiolaria accidentally entangled in the arachnoidal framework of
various Sagosphærida, I think it much more probable, that that "triple
medullary shell," composed of three simple concentric lattice-spheres, was
really a species of _Plegmosphæra_ or _Actinomma_, accidentally entangled
in the arachnoidal spongy framework of _Sagmarium_. This is the more
probable, as I had observed very frequently at Messina, in 1859, fragments
of that framework, but only once the triple lattice-shell which I supposed
to be the "triple medullary shell" of the former. The peculiar structure of
the loose framework, its very large triangular meshes and thin arachnoidal
bars, partly provided with cruciate verticils (_loc. cit._, Taf. xxvi.
figs. 4, 5) have been very frequently observed by me during the last ten
years in various Sagosphærida (PHÆODARIA), but never in any true
#Sphæroidea# (SPUMELLARIA).
The second species of Sagosphærida hitherto observed, is _Sagoscena
gracilis_, described and figured in 1879 by Richard Hertwig as _Aulosphæra
gracilis_ (Organism. {1603}d. Radiol., p. 91, Taf. ix. fig. 4). He too
observed only fragments of destroyed and incomplete shells, and was led by
their striking similarity to fragments of _Aulosphæra elegantissima_ to
unite it with the genus _Aulosphæra_. But the accurate description and the
figure given by him of the fragments observed leaves no doubt that it was a
true _Sagoscena_.
In the collection of the Challenger the Sagosphærida are so common and so
richly represented, that we may describe here not less than seven genera
and thirty-three species, but this may be a small part only of the numerous
species of this family, which seems to be widely distributed over all
oceans, in the Arctic and Antarctic as well as in temperate and tropical
zones. The majority are inhabitants of the surface, but a few species have
been found only in deep-sea soundings. A striking fact is their usual
association with the similar Aulosphærida. The majority of shells of both
families were found entangled in one another.
The shell of all Sagosphærida seems to be spherical or nearly spherical in
the complete state; but complete spheres can be observed only very rarely,
and it is not impossible that deviations from the spherical form exist just
as in some Aulosphærida (_e.g._, the lenticular _Aulophacus_ and the
spindle-shaped _Aulatractus_). The diameter of the spheres usually seems to
be between 1 and 2, often also 3 millimetres; very rarely shells occur
which are less than 1 or more than 3 (4 or 5) millimetres.
The siliceous network or lattice-work of the Sagosphærida exhibits a very
characteristic shape, and this enables one to distinguish it at first sight
from all the other Radiolaria. It is constantly composed of triangular,
very large meshes, which are separated by very thin and delicate, flexible
and elastic bars. With respect to the arrangement of these meshes we
distinguish two different subfamilies; in the Sagenida the wall of the
spherical shell is very thin and composed only of a simple lattice-plate;
in the Sagmarida the wall is thickened and spongy, with a complete
wicker-work of threads, interwoven in different directions.
The typical triangular form of the large meshes is usually regular or
subregular in the fenestrated Sagenida, more or less irregular in the
spongy Sagmarida. In many cases, however, irregular triangles also occur in
the former, and regular triangles in the latter subfamily. Very rarely
irregular polygonal meshes are found in a part of the network, small
connecting bars being developed accidentally between two neighbouring sides
of the triangles. The diameter of the meshes is usually between 0.1 and 0.2
mm., often also greater, between 0.2 and 0.3, rarely smaller, 0.05 to 0.09
mm. The triangular meshes of the Sagosphærida are therefore on an average
ten times as large as the usual meshes in the network of the common
#Sphæroidea#.
The filiform bars, or the thread-shaped, very long and thin rods between
the triangular meshes, are scarcely less characteristic of the Sagosphærida
than the form and size of the meshes. Their length is usually between 0.1
and 0.2 mm., often also {1604}from 0.2 to 0.3 mm., whilst their thickness
is only 0.002 to 0.004 mm., often it is less than 0.001, rarely more than
0.005 mm. The nodal points of the network, in which six threads are usually
united, are more or less thickened, often stellate (Pl. 108, figs. 9, 12,
&c.). Sometimes they are pierced by a central pore. The thin threads are
constantly cylindrical, never edged or prismatic, very elastic and
flexible; usually they are perfectly smooth, rarely spiny or thorny,
sometimes provided with scattered cruciate verticils of lateral branches,
as in _Sagena crucifera_ and in the first described form of this family,
_Sagmarium trigonizon_ (compare my Monograph, 1862, Taf. xxvi. fig. 5).
The surface of the spherical shell is smooth only in two genera of
Sagosphærida, in _Sagena_ and _Sagmarium_ (Pl. 108, figs. 2, 8). In the
five other genera it is covered either with radial spines, arising from the
nodal points of the network, or with peculiar cortical pyramids or
tent-shaped elevations (Pl. 108, figs. 1, 3-6, &c.). These pyramids are of
the same characteristic shape as in the similar _Auloscena_ among the
Aulosphærida (Pl. 110, fig. 1); usually, however, they are less regular
than in the latter. The pyramids or tents are usually six-sided, often,
however, they are also four-sided or three-sided, more rarely five, seven
or more sided. The edges of the pyramids are formed by filiform bars
similar to those which compose the original lattice-work of the
Sagosphærida. The cavity of the pyramids is quite simple in _Sagoscena_
(figs. 1, 5, 6), whilst in _Sagenoscena_ and _Sagoplegma_ a radial column
arises in its axis, the thickened axial rod (figs. 3, 4, 10).
The radial spines, which arise either from the tops of the pyramids or from
the nodal points of the network, exhibit in the Sagosphærida a variety and
elegance similar to the closely allied Aulosphærida. Sometimes a single
radial spine arises in each nodal point or at the top of each pyramid
(figs. 3, 4, 10); at other times two, three, or four (rarely more)
divergent spines (figs. 6-9, 12, 13). These are rarely quite simple,
usually provided with lateral and terminal branches. The lateral branches
are either scattered irregularly, or regularly disposed in elegant
verticils, each of which is usually composed of three or four short
branches (Pl. 108, figs. 9, 13). The terminal branches form either a
similar verticil, or a bunch or corona, composed of numerous radial
secondary spines. The distal ends of the terminal as well as of the lateral
branches are rarely simple, usually they are provided with a spinulate knob
or with an elegant spathilla (Pl. 108, figs. 3, 9, 13).
The _central capsule_ of the Sagosphærida is comparatively small, as it
also is in the Aulosphærida and Orosphærida. Its diameter is usually about
one-third or one-fourth that of the enveloping shell, between 0.2 and 0.3,
often only 0.12 to 0.18, rarely more than 0.3 mm. It is surrounded on the
oral half by a red or dark phæodium and separated from the inner surface of
the shell by the voluminous calymma. The subspherical nucleus is usually
about half as broad as the capsule. The three openings of the latter, the
large tubular astropyle and the two opposite lateral parapylæ, exhibit the
same shape {1605}as in the closely allied Aulosphærida (Pl. 111, fig. 3).
The pseudopodia arising from the central capsule form a loose network in
the calymma, and proceed over its surface as numerous delicate radial
filaments, often supported by the radial spines.
_Synopsis of the Genera of Sagosphærida._
-------------------------------------------------------------------------
I. Subfamily Sagenida.
Wall of the spherical shell composed of a simple lattice-plate with
or without pyramidal elevations.
-------------------------------------------------------------------------
{ No radial spines, surface
Surface of the spherical { smooth, 675. _Sagena_.
shell smooth or spiny, {
without pyramidal { Radial spines in the nodal
elevations. { points, 676. _Sagosphæra_.
Surface of the spherical { Pyramids without internal
shell covered with { axial rod, 677. _Sagoscena_.
pyramidal or tent- {
shaped elevations. { Pyramids with an internal
{ radial axial rod, 678. _Sagenoscena_.
-------------------------------------------------------------------------
II. Subfamily Sagmarida.
Wall of the spherical shell spongy, composed of an irregular
complicated wicker-work.
-------------------------------------------------------------------------
Surface of the spherical { Surface smooth, without
shell smooth or spiny, { radial spines, 679. _Sagmarium_.
without pyramidal {
elevations. { Surface studded with
{ radial spines, 680. _Sagmidium_.
Surface of the spherical { Pyramids on the top with a
shell covered with { radial spine or a bunch
pyramidal elevations. { of divergent spines, 681. _Sagoplegma_.
Subfamily 1. SAGENIDA, Haeckel.
_Definition._--#Sagosphærida# with a delicate spherical shell, the thin
wall of which is composed of a simple lattice-plate, not spongy.
Genus 675. _Sagena_,[294] n. gen.
_Definition._.--#Sagosphærida# with a delicate shell, the thin wall of
which is composed of a simple smooth lattice-plate, without radial spines.
The genus _Sagena_ is the simplest of the Sagosphærida and may be regarded
as the common ancestral form of this family. The delicate wall of the
simple spherical lattice-shell is composed of large, regular, or
subregular, triangular meshes, the nodal points of which bear no radial
spines. It agrees therefore perfectly with _Aularia_, and differs from this
simplest form of Aulosphærida only in the structure of the skeleton, which
is composed not of hollow articulated tubes, but of very thin solid
threads. The skeleton may therefore also be confounded with _Cenosphæra_,
but the central capsule of this latter is "peripylean," with numerous fine
pores in the entire wall, whilst that of _Sagena_ is "tripylean," having
the proboscis of all PHÆODARIA.
{1606}1. _Sagena ternaria_, n. sp. (Pl. 108, fig. 8).
Network subregular, with equilateral triangular meshes, intermingled with
single irregular meshes (fig. 8). Bars of the network smooth, its nodal
points solid, not pierced.
_Dimensions._--Diameter of the spherical shell 1.5 to 2.5, length of the
bars 0.1 to 0.2, breadth 0.002 to 0.005.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific,
surface.
2. _Sagena pertusa_, n. sp.
Network subregular, with nearly equal triangular meshes. Bars of the
network smooth, its nodal points pierced by a circular hole.
_Dimensions._--Diameter of the shell 1.2 to 1.8, length of the bars 0.2 to
0.25, breadth 0.003.
_Habitat._--Central Pacific, Stations 270 to 274, surface.
3. _Sagena triangula_, n. sp.
Network very regular, with equilateral triangular meshes. Bars of the
network spinulate, like those of _Sagoplegma spinulosa_. (Pl. 108, fig.
14), its nodal points solid, not pierced.
_Dimensions._--Diameter of the shell 2.2, length of the bars 0.25, breadth
0.004.
_Habitat._--South Atlantic, Station 325, surface.
4. _Sagena crucifera_, n. sp.
Network more or less irregular, with unequal triangular meshes. Bars of the
network studded with scattered, rectangular, minute crosses, arising
perpendicularly, each cross composed of four small equal bars. Nodal points
partly solid, partly pierced by a hole. Network very similar to that of
_Dictyosoma trigonizon_, figured in my Monograph, Taf. xxvi. figs. 4, 5.
_Dimensions._--Diameter of the shell 1.5, length of the bars 0.1 to 0.2,
breadth 0.003.
_Habitat._--Mediterranean, Atlantic, Canary Islands, Station 353, surface.
Genus 676. _Sagosphæra_,[295] n. gen.
_Definition._--#Sagosphærida# with a delicate spherical shell, the thin
wall of which is composed of a simple lattice-plate, and bears on its nodal
points radial spines.
The genus _Sagosphæra_ differs from the preceding _Sagena_, its ancestral
form, in the development of radial spines on the nodal points of the simple
delicate lattice-sphere. It exhibits therefore the same relation to the
latter as _Aulosphæra_ bears to _Aularia_. {1607}The regular or subregular
triangular meshes of the lattice-sphere are separated in _Sagosphæra_ by
solid, very thin threads, in the similar _Aulosphæra_, however, by thicker
hollow tubes. The genus _Sagosphæra_ may be divided into two
subgenera:--_Sagosphærella_ with a single radial spine at each nodal point
of the network, and _Sagosphæroma_ with a bunch of two to four or more
divergent radial spines.
1. _Sagosphæra trigonilla_, n. sp.
Radial spines simple, straight, smooth, about as long as the smooth bars of
the network, a single one at each nodal point. Meshes very regular, of
equal size, equilateral triangular. (Similar to the common _Aulosphæra
trigonopa_.)
_Dimensions._--Diameter of the sphere 1.2 to 1.8, length of the bars 0.1 to
0.2, breadth 0.002 to 0.006.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.
2. _Sagosphæra penicilla_, n. sp. (Pl. 108, fig. 10).
Radial spines straight, stout, a single one at each nodal point, twice as
thick, but of the same length as the smooth bars of the network, armed at
the distal end with a brush of numerous thin radial bristles. (Very similar
to _Sagenoscena penicillata_, but without pyramidal elevations on the
surface of the sphere.)
_Dimensions._--Diameter of the sphere 1.0 to 1.5, length of the bars 0.1 to
0.15, breadth 0.002 to 0.004.
_Habitat._--Antarctic Ocean, Station 154, surface.
3. _Sagosphæra verticilla_, n. sp.
Radial spines slender, slightly curved, a single one at each nodal point,
armed with three to five cruciate verticils, each of which is composed of
four crossed lateral branches with spinulate terminal knobs (similar to
_Sagmidium crucicorne_, Pl. 108, fig. 9), but with a spherical shell,
having a simply latticed, and not a spongy wall.
_Dimensions._--Diameter of the sphere 2.0 to 2.5, length of the bars 0.1 to
0.2, breadth 0.002.
_Habitat._--North Pacific, Station 256, surface
4. _Sagosphæra furcilla_, n. sp. (Pl. 108, figs. 11, 11_a_).
Radial spines short, spinulate, with a spiny terminal knob (fig. 11_a_),
two or three arising from each nodal point of the network in divergent
directions, only one-third or one-fourth as long as its smooth bars. Meshes
more or less irregular, triangular.
_Dimensions._--Diameter of the sphere 2.2, length of the bars 0.2 to 0.3,
breadth 0.004.
_Habitat._--South Pacific, Station 293, depth 2025 fathoms.
{1608}5. _Sagosphæra coronilla_, n. sp.
Radial spines slender, smooth, three to six arising from each nodal point
of the network in divergent directions, about as long as its smooth bars,
crowned at the distal end with a bunch of twenty to thirty radial terminal
branches, and provided with a spinulate knob at the distal end (similar to
_Sagenoscena stellata_, Pl. 108, fig. 3).
_Dimensions._--Diameter of the sphere 3.0, length of the bars 0.1 to 0.2,
breadth 0.002.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
Genus 677. _Sagoscena_,[296] n. gen.
_Definition._--#Sagosphærida# with a delicate spherical shell, the thin
wall of which is composed of a simple lattice-plate and covered with
numerous pyramidal elevations; each pyramid bears on its top one or more
radial spines, but has no axial rod in its radial axis.
The genus _Sagoscena_, and the following closely allied _Sagenoscena_ (both
very common and widely distributed), exhibit a peculiar and very remarkable
structure of the delicate lattice-shell, similar to that which _Auloscena_
represents among the Aulosphærida. The surface of the simple spherical
lattice-shell is covered with numerous pyramidal or tent-shaped elevations.
These elegant and delicate pyramids are, however, in _Sagoscena_ usually
not so regular as in the similar _Auloscena_; the edges of the pyramids are
in the latter hollow cylindrical tubes, in the former thin solid threads.
The top of each pyramid usually bears a bunch of apical spines.
1. _Sagoscena castra_, n. sp. (Pl. 108, fig. 1).
Pyramids subregular, of equal size and similar form, usually three-sided,
crowned at the top with three divergent apical spines, which alternate with
the three edges of the pyramids and bear a small spinulate terminal knob.
(Some four-sided and single five-sided pyramids are often intermingled with
the three-sided.)
_Dimensions._--Diameter of the sphere 1.7 to 2.3, length of the bars 0.2 to
0.25, breadth 0.008.
_Habitat._--South-Eastern Pacific, Stations 295, 296, surface.
2. _Sagoscena tentorium_, n. sp. (Pl. 108, fig. 6).
Pyramids subregular, of equal size and similar form, usually four-sided,
crowned at the top with three divergent apical spines, which are trifurcate
at the distal end. (Some three-sided and five-sided pyramids are often
intermingled with the four-sided.)
_Dimensions._--Diameter of the sphere 2.2, length of the bars 0.2 to 0.25,
breadth 0.005.
_Habitat._--South Pacific, Station 291, surface.
{1609}3. _Sagoscena prætorium_, n. sp. (Pl. 108, fig. 7).
Pyramids subregular, of equal size and similar form, usually four-sided,
crowned at the distal top with three or four divergent apical spines, which
bear some irregular verticils of lateral and terminal branches. (Some
five-sided and some six-sided pyramids are often intermingled with the
four-sided.)
_Dimensions._--Diameter of the sphere 2.6, length of the bars 0.3, breadth
0.006.
_Habitat._--Central Pacific, Stations 271 to 274, surface.
4. _Sagoscena pellorium_, n. sp. (Pl. 108, fig. 5).
Pyramids subregular, of equal size and similar form, usually five-sided or
six-sided, crowned at the distal end with three to six divergent apical
spines, which bear an irregularly spinulate terminal knob. (The size and
form of the apical spines is here very variable, as well as the number of
the edges of the pyramids, which varies between three and six.)
_Dimensions._--Diameter of the sphere 3.2, length of the bars 0.15 to 0.25,
breadth 0.008.
_Habitat._--Antarctic Ocean, Station 156, surface.
5. _Sagoscena cruciarium_, n. sp.
Pyramids subregular, usually six-sided (intermingled with single five-sided
and seven-sided or eight-sided forms), crowned at the distal top with three
divergent, slender, apical spines, each of which bears three to six regular
cruciate verticils; the four crossed lateral branches of each verticil
bearing a spinulate terminal knob. (Similar to _Sagoplegma scenophora_, Pl.
108, fig. 13.)
_Dimensions._--Diameter of the shell 2.5, length of the bars 0.2 to 0.3,
breadth 0.004.
_Habitat._--North Pacific, Stations 240 to 244, surface.
6. _Sagoscena debilis_, n. sp.
Pyramids more or less irregular, with four, five, or six sides, of somewhat
different form and unequal size; crowned at the top with one, two, or three
slender apical spines, of variable length. These spines as well as the bars
of the network bear scattered cruciate verticils, each usually composed of
four crossed, small, lateral branches.
_Dimensions._--Diameter of the shell 2 to 3.0, length of the bars 0.1 to
0.15, breadth 0.003.
_Habitat._--Central Pacific, Stations 263 to 274, surface.
7. _Sagoscena gracilis_, Haeckel.
_Aulosphæra gracilis_, R. Hertwig, 1879, Organism. d. Radiol., p. 91,
Taf. ix. fig. 4.
Pyramids more or less irregular, with five, six, or seven sides, often of
somewhat different form and unequal size; crowned at the top with a single
radial spine, which has the same size as the {1610}bars of the network, and
bears in its distal half four cruciate verticils, each composed of four
crossed and curved horizontal branches.
_Dimensions._--Diameter of the sphere 1 to 2, length of the bars 0.08 to
0.09, breadth 0.002.
_Habitat._--Mediterranean (Messina), surface.
8. _Sagoscena fragilis_, n. sp.
Pyramids very irregular, with four to eight sides, of different form and
unequal size; crowned at the top with a single, slender, radial spine, of
the same thickness as the slender bars of the network; the latter as well
as the former are smooth, without lateral branches.
_Dimensions._--Diameter of the sphere 1.0 to 2.0, length of the bars 0.1 to
0.2, breadth 0.001 to 0.002.
_Habitat._--Cosmopolitan; Atlantic, Pacific, surface.
Genus 678. _Sagenoscena_,[297] n. gen.
_Definition._--#Sagosphærida# with a delicate spherical shell, the thin
wall of which is composed of a simple lattice-plate and covered with
numerous pyramidal elevations; each pyramid bears on its top one or more
radial spines, and has an internal axial rod in its radial axis.
The genus _Sagenoscena_ differs from the preceding closely allied
_Sagoscena_ in the possession of an internal radial axial rod, which arises
in the centre of the base of each pyramid, and is prolonged usually over
its apex into a free, radial, apical spine. The distal end of the latter is
usually armed with a bunch of terminal teeth or bristles. In the similar
_Sagoscena_ the internal cavity of the pyramids is simple, without axial
rod.
1. _Sagenoscena stellata_, n. sp. (Pl. 108, fig. 3).
Pyramids rather regular, usually six-sided (intermingled with single
five-sided and four-sided forms); their axial rod and its prolongation, the
radial apical spine, three to four times as thick as the slender edges of
the pyramid. The distal end of the apical spine bears an elegant star of
numerous radially divergent terminal branches, each of which is armed with
a spinulate terminal knob.
_Dimensions._--Diameter of the sphere 3.5 to 4.0, length of the net bars
0.3, breadth 0.003; length of the radial spines 0.2, breadth 0.012.
_Habitat._--South Atlantic, Station 318, depth 2040 fathoms.
2. _Sagenoscena ornata_, n. sp. (Pl. 108, fig. 4).
Pyramids rather regular, usually six-sided (intermingled with single
five-sided and seven-sided forms); their axial rod and apical spine
spindle-shaped, two to four times as thick as the smooth bars {1611}of the
network. The distal end of the radial spines bears an elegant, foliate,
terminal knob, composed of four to six vertical pinnate leaves, lying in
crossed meridional planes.
_Dimensions._--Diameter of the sphere 2 to 3, length of the rods 0.1 to
0.2, breadth 0.003 to 0.01.
_Habitat._--Antarctic Ocean, Station 156, depth 1975 fathoms.
3. _Sagenoscena penicillata_, n. sp. (Pl. 108, fig. 10).
Pyramids rather regular, usually six-sided (intermingled with single
five-sided, seven-sided, and eight-sided forms); their axial rod and apical
spine spindle-shaped, thicker than the smooth bars of the network. The
distal end of the radial spines is penicillate and bears a brush of
bristle-shaped, radial, terminal spinules (compare _Sagosphæra penicilla_,
p. 1607).
_Dimensions._--Diameter of the sphere 1 to 1.5, length of the bars 0.1 to
0.15, breadth 0.004 to 0.005.
_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.
4. _Sagenoscena coronata_, n. sp.
Pyramids rather regular, usually four-sided (intermingled with single
five-sided and six-sided forms); their axial rod and apical spines
cylindrical, scarcely thicker than the smooth bars of the network. The
distal end of the radial spines bears a corona of twenty to thirty curved
terminal branches, which form a regular circle, and are armed with a
spinulate terminal knob.
_Dimensions._--Diameter of the sphere 2 to 3, length of the bars 0.12 to
0.18, breadth 0.004 to 0.008.
_Habitat._--North Pacific, Station 256, surface.
5. _Sagenoscena spathillata_, n. sp.
Pyramids more or less irregular, of different sizes and various forms, each
composed of four to eight convergent rods and a central axial rod. The
latter is prolonged into a free apical spine, which bears at the distal end
a spathilla of eight to twelve recurved teeth, and often beyond it a second
similar verticil.
_Dimensions._--Diameter of the sphere 4.0, length of the bars 0.1 to 0.2,
breadth 0.002.
_Habitat._--Arctic Ocean, Greenland (Olrik).
6. _Sagenoscena cruciata_, n. sp.
Pyramids very irregular, of different sizes and various forms, each
composed of six to nine convergent rods and a central axial rod. The latter
is prolonged into a free apical spine, which bears three to five cruciate
verticils, each composed of four perpendicularly crossed lateral branches
which bear at the distal end a spinulate knob (similar to _Sagmidium
crucicorne_, Pl. 108, fig. 9).
_Dimensions._--Diameter of the sphere 1.0 to 1.2, length of the bars 0.06
to 0.09, breadth 0.001.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
{1612}Subfamily 2. SAGMARIDA, Haeckel.
_Definition._--#Sagosphærida# with a spongy spherical shell, the thickened
wall of which is composed of a loose spongy framework.
Genus 679. _Sagmarium_,[298] n. gen.
_Definition._--#Sagosphærida# with a spongy spherical shell, the thickened
wall of which is composed of a loose spongy framework, and exhibits a
smooth surface, without radial spines and pyramidal elevations.
The genus _Sagmarium_, and the following two genera of Sagosphærida,
represent together the subfamily Sagmarida, differing from the preceding
Sagenida in the spongy structure of the shell-wall. Whilst in the latter
the thin wall of the delicate spherical shell is composed of a simple
lattice-plate with triangular meshes, in the former numerous branches
diverge from the nodal points of these meshes, and produce by union an
irregular and loose spongy framework. The surface of this spongy hollow
sphere (similar to _Plegmosphæra_) is in _Sagmarium_ smooth.
1. _Sagmarium spongodictyum_, n. sp. (Pl. 108, fig. 2).
Spongy wall of the hollow sphere about half as thick as the radius of its
cavity. Bars of the spongy framework very thin and fragile, smooth, without
thorns.
_Dimensions._--Diameter of the sphere 2.0 to 2.4; length of the bars 0.1 to
0.2, breadth 0.001.
_Habitat._--South Atlantic, Station 333, surface.
2. _Sagmarium plegmosphærium_, n. sp. (Pl. 108, fig. 14).
Spongy wall of the hollow sphere about one-fourth as thick as the radius of
its cavity. Bars of the spongy framework rather stout, studded with
numerous small spines, which arise perpendicularly from their surface.
_Dimensions._--Diameter of the sphere 1.2 to 1.5, length of the bars 0.1 to
0.16, breadth 0.004.
_Habitat._--Tropical Atlantic, Station 347, surface.
3. _Sagmarium trigonizon_, Haeckel.
_Dictyosoma trigonizon_, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 841.
_Spongodictyon trigonizon_, Haeckel, 1863, Monogr. d. Radiol., p. 459,
Taf. xxvi. figs. 4, 5.
Bars of the spongy framework thin, irregularly curved, bearing scattered
small crosses, which are composed of four small rods arising
perpendicularly from the bars. Nodal points of the {1613}framework partly
pierced by a hole. The peculiar network of a complete specimen, observed by
me at Portofino in 1880, was so similar to that of _Spongodictyon
trigonizon_, described above (p. 91), and figured in 1862 in my Monograph,
that I am doubtful if the two forms are not identical, the two medullary
shells of the latter being accidentally entangled in the framework.
(Compare p. 1602.)
_Dimensions._--Diameter of the sphere 1.1 to 1.5, length of the bars 0.1 to
0.2, breadth 0.002.
_Habitat._--Mediterranean (Messina, Portofino), surface.
Genus 680. _Sagmidium_,[299] n. gen.
_Definition._--Sagosphærida with a spongy spherical shell, the thickened
wall of which is composed of a loose spongy framework, and bears on the
nodal points of its surface radial spines.
The genus _Sagmidium_ differs from the preceding _Sagmarium_ in the
development of radial spines on the surface of the spongy hollow sphere. It
bears therefore the same relation to the latter as _Sagosphæra_ does to
_Sagena_, and may be derived either from _Sagmarium_ by the formation of
radial spines, or from _Sagosphæra_ by development of the spongy envelope.
1. _Sagmidium unicorne_, n. sp.
Radial spines simple, straight, smooth, a single one at each nodal point of
the surface of the spongy sphere, bearing on its distal end a spinulate
knob, or a bunch of numerous radial bristles. (Similar to _Sagenoscena
penicillata_, Pl. 108, fig. 10.) Bars of the spongy framework smooth.
_Dimensions._--Diameter of the sphere 3.0 to 3.5, length of the bars 0.15
to 0.2, breadth 0.003 to 0.006.
_Habitat._--Antarctic Ocean, Station 256, surface.
2. _Sagmidium tricorne_, n. sp.
Radial spines simple, smooth, usually three divergent united at each nodal
point of the surface (sometimes two or four instead of three). Each spine
bears on its distal end three short divergent conical teeth. (Similar to
the terminal teeth of _Sagoscena tentorium_, Pl. 108, fig. 6.) Bars of the
spongy framework smooth.
_Dimensions._--Diameter of the sphere 1.6 to 2.4, length of the bars 0.06
to 0.09, breadth 0.001 to 0.002.
_Habitat._--Central Pacific, Stations 263 to 268, surface.
3. _Sagmidium crucicorne_, n. sp. (Pl. 108, fig. 9).
Radial spines slender, verticillate, three or four divergent arising from
each nodal point of the surface. Each spine bears three to six cruciate
verticils of lateral branches; each verticil being {1614}composed of four
crossed small branches with a spinulate terminal knob. Bars of the spongy
framework partly covered with similar verticils.
_Dimensions._--Diameter of the sphere 2.0 to 3.0, length of the bars 0.2 to
0.3, breadth 0.002 to 0.003.
_Habitat._--North Pacific, Stations 240 to 244, surface.
4. _Sagmidium quadricorne_, n. sp. (Pl. 108, fig. 12).
Radial spines stout, smooth, cylindrical, usually four divergent arising
from each nodal point of the surface (sometimes three, five, or six,
instead of four). Each spine bears on its distal end a club-shaped stellate
knob. Bars of the spongy framework smooth.
_Dimensions._--Diameter of the sphere 4.5, length of the bars 0.2 to 0.3,
breadth 0.003 to 0.005.
_Habitat._--South Pacific, Station 293, depth 2025 fathoms.
5. _Sagmidium multicorne_, n. sp.
Radial spines slender, more or less curved, verticillate, in variable
number (three to six) divergent, arising from the nodal points of the
surface. The spines as well as the bars of the spongy framework are partly
simple, partly covered with irregularly scattered cruciate verticils, very
similar to those of _Sagmarium trigonizon_ (or _Dictyosoma trigonizon_),
figured in my Monograph, pl. xxvi. figs. 4, 5.
_Dimensions._--Diameter of the sphere 5.0, length of the bars 0.2 to 0.3,
breadth 0.003.
_Habitat._--Indian Ocean, Cocos Islands (Rabbe), surface.
Genus 681. _Sagoplegma_,[300] n. gen.
_Definition._--#Sagosphærida# with a spongy spherical shell, the thickened
wall of which is composed of a loose spongy framework, and bears on its
surface numerous pyramidal elevations.
The genus _Sagoplegma_ differs from _Sagmarium_, its ancestral form, in the
development of pyramidal or tent-shaped elevations on the surface of the
spongy hollow sphere. It exhibits, therefore, the same relation to the
latter as the similar _Sagoscena_ bears to _Sagena_. The wall of the
spherical shell is in the two latter genera a thin simple lattice-plate, in
the former a thickened spongy framework.
1. _Sagoplegma pyramidophora_, n. sp.
Pyramids on the surface of the spongy sphere subregular, mostly
tetrahedral, of nearly equal size and similar form. The three edges of each
pyramid are prolonged over its top into three {1615}short, divergent,
apical spines which are forked at the distal end. (Very similar to
_Sagoscena castra_ and _Sagoscena tentorium_, Pl. 108, figs. 1, 6, probably
derived from them, but differing in the spongy structure of the thickened
shell-wall, which is half as thick as the radius of its cavity.)
_Dimensions._--Diameter of the sphere 2.0 to 2.5, length of the bars 0.15
to 0.2, breadth 0.002.
_Habitat._--North Pacific, Stations 231 to 239, surface.
2. _Sagoplegma scenophora_ n. sp. (Pl. 108, fig. 13).
Pyramids on the surface of the spongy sphere irregular, with three to six
sides, unequal in size and different in form. The edges of each pyramid are
prolonged over its top into three to six divergent apical spines, which
bear three to six cruciate verticils, each composed of four small, crossed,
lateral branches, armed with a spinulate knob at the distal end.
_Dimensions._--Diameter of the sphere 3.0 to 3.5, length of the bars 0.25
to 0.35, breadth 0.003.
_Habitat._--North Pacific, Stations 252, 253, surface.
Family LXXVI. #AULOSPHÆRIDA#, Haeckel (Pls. 109-111).
_Aulosphærida_, Haeckel, 1862, Monogr. d. Radiol., p. 357.
_Definition._--PHÆODARIA with a large spherical or subspherical (rarely
spindle-shaped) articulated shell, which is composed of hollow tangential
tubes. Nodal points of the loose network stellate, with a nodal cavity and
astral septa. Meshes either triangular or polygonal. Hollow radial spines
arise usually at the nodal points of the surface. No peculiar mouth in the
shell. Central capsule tripylean, placed in the centre of the shell.
The family #Aulosphærida# comprises a great number of splendid and widely
distributed PHÆODARIA, which have a special interest on account of the
peculiarly complicated structure of their large lattice-shell, of the
extraordinary beauty of their form and of their remarkable relations to the
other PHÆODARIA. They differ from all the other Radiolaria in the peculiar
articulate composition of the spherical skeleton of hollow tangential
tubes, which are connected (and at the same time separated) by sutural or
astral septa and filled up by jelly. The same peculiar structure recurs
only in the closely allied Cannosphærida, which, however, differ in the
possession of a second internal concentric shell, connected with the outer
by radial beams. The similar Sagosphærida, which exhibit corresponding
forms in various genera, differ from the Aulosphærida in the simpler
structure of the delicate lattice-sphere, which is composed of very thin
solid threads of silica, without astral septa. The Orosphærida, finally,
also nearly related to the preceding families, differ from them in the
coarse structure of the lattice-sphere, which is composed of very thick
tangential, concentrically stratified rods, with an internal axial canal,
but without astral septa at the nodal points.
{1616}One genus only, and two species, of Aulosphærida have been hitherto
known, having been discovered by me in 1859 at Messina, and described in my
Monograph in 1862 as _Aulosphæra trigonopa_ and _Aulosphæra elegantissima_
(_loc. cit._, p. 357, Taf. x. figs. 4, 5; Taf. ix. figs. 5, 6). The
characteristic structure of their central capsule, as true TRIPYLEA, was
afterwards, in 1879, described more accurately by Richard Hertwig
(Organism. d. Radiol., p. 90, Taf. x. figs. 2, 8, 14). The rich collection
of the Challenger has demonstrated that the Aulosphærida belong to the most
common and most widely distributed PHÆODARIA; many of them are
distinguished by the admirable elegance and astonishing regularity of their
large and delicate shell. Nine genera and fifty-six species of this great
family are described in the following pages, which, however, may represent
only a small part of the numerous forms which are found on the surface as
well as in different depths of all oceans and in all zones.
The shell is in the great majority of Aulosphærida a regular sphere or an
endospherical polyhedron. Two genera only, both rather rare, exhibit a
different monaxonial form, one vertical main axis being developed either
more or less than all the other ones of the sphere:--_Aulatractus_ is
spindle-shaped or ellipsoidal, with prolonged main axis; _Aulophacus_ is
lenticular or discoidal, with shortened main axis. The former may be
compared to the #Prunoidea#, the latter to the #Discoidea#, in opposition
to the common regular #Sphæroidea#. The size of the lattice-shell is very
considerable in all Aulosphærida, its diameter varying usually between 1
and 3 mm., often it amounts to 4 or 5 mm.; very rarely the diameter is more
than 5 or less than 1 mm. The largest form observed is the spindle-shaped
_Aulatractus_, in which the vertical prolonged main axis attains 6 to 10
mm., the horizontal equatorial axis 3 to 5 mm.
The network of the lattice-shell exhibits in the Aulosphærida two different
types, according to which we distinguish two different subfamilies:
Aularida and Aulonida; the former are much more common and richer in
remarkable forms than the latter. The meshes of the network are in the
Aularida constantly triangular, regular or subregular, and very similar to
those of the Sagosphærida; at each nodal point six tangential tubes are
usually united, so that the network may be regarded also as composed of
regular hexagonal meshes, each of which is divided into six smaller
triangular meshes (Pl. 109, figs. 1, 3, 5). The second subfamily, the
Aulonida, are much rarer than the former, and are distinguished by the
polygonal meshes of the network; these are usually more or less irregular,
pentagonal and hexagonal intermingled, more rarely tetragonal, heptagonal,
or octagonal; usually three or four, rarely five or more tangential tubes
are united at each nodal point (Pl. 111, figs. 1, 3). The size of the
meshes is very considerable, and agrees with that of the Sagosphærida;
their diameter being usually between 0.1 and 0.3, rarely less or more.
The hollow tubes which compose the loose network are usually cylindrical,
straight or slightly curved, smooth (Pl. 111, fig. 2), more rarely somewhat
spinulate (Pl. 109, {1617}fig. 5). Their length is usually between 0.1 and
0.2 mm., rarely less than 0.08, or more than 0.24 mm.; their diameter
usually between 0.003 to 0.005, sometimes only 0.002 or less, at other
times 0.006 or more. In several species the tangential tubes are thinner in
the middle part, and thickened towards the two ends (Pl. 109, figs. 3, 4).
Each tube consists of a thin cylindrical wall of silex, and of a jelly-mass
filling up its cavity; in its axis runs a very thin, straight or slightly
curved thread of silica, the axial filament.
The arrangement of the tangential tubes, which originally, in the simplest
Aulosphærida, lie tangentially in the spherical face of a simple
lattice-sphere, exhibits various secondary modifications, leading to
various interesting generic forms. Two genera only, _Aularia_ (with
triangular meshes, Pl. 111, fig. 2) and _Aulonia_ (with polygonal meshes,
Pl. 111, fig. 1) possess a smooth, perfectly simple lattice-sphere, and may
therefore be regarded as the ancestral genera of the two subfamilies. Two
other corresponding genera, the common _Aulosphæra_ (Pl. 109) and the rarer
_Aulastrum_ (Pl. 111, fig. 3), differ from the former in the development of
radial spines at the nodal points of the simple lattice-sphere.
_Aulophacus_ may be developed from _Aulosphæra_ by shortening,
_Aulatractus_, however, by prolongation of the vertical main axis (Pl. 111,
figs. 6, 7). In two genera, _Auloplegma_ and _Aulodictyum_, the latticed
wall of the spherical shell becomes thickened and spongy, an irregular
framework being formed by tubes connected in different directions (Pl. 111,
fig. 8). The most remarkable and the most elegant form, however, of the
whole family is represented by _Auloscena_ (Pl. 110). The entire surface of
the spherical lattice-shell is here covered with numerous regular or
subregular pyramids, or tent-shaped elevations. Usually each pyramid is
six-sided, and surrounded by six other six-sided pyramids, their bases
being separated by six triangular meshes, which lie in the spherical face.
A similar elegant form is developed among the Sagosphærida in the genera
_Sagoscena_, _Sagenoscena_ and _Sagoplegma_ (Pl. 108, fig. 1). The
structure of _Auloscena_, however, is usually more regular, and in the top
of each pyramid a radial tube arises.
The junction of the cylindrical tubes at the nodal points of the network is
very remarkable. _Aularia_, the simplest form of the family, exhibits at
each nodal point the union of six tangential tubes (Pl. 111, fig. 2); their
ends are so pointed and truncated that they are connected in the form of a
regular six-radiate star; the conical end of each tube is separated from,
and at the same time closely connected with, the adjacent conical ends of
the two neighbouring tubes by a thin septum, the astral or sutural septum.
The six astral septa compose together a six-radiate star, and in the centre
of this star the six axial filaments of the tubes are united. Their central
union is surrounded by a small, double-contoured circle, and this circle
seems to be the perimeter of a small and flat cavity on the inside of the
star, which we call shortly the "nodal cavity" ("die kleine Vertiefung"
according to Hertwig, _loc. cit._, p. 90). The nodal cavity of _Aularia_
probably possesses a central opening on its inside and six small
surrounding pores, which {1618}lead into the six connected tangential
tubes. In _Aulosphæra_ and _Auloscena_, where a radial spine arises at each
nodal point, its axial filament arises from the centre of the star, and is
usually prolonged on the inside into a free centripetal beam (Pl. 109,
figs. 6, 7; Pl. 110, figs. 4, 6). This centripetal beam is a slender, very
thin, conical tube (often with a six-sided pyramidal base) and perhaps of
great morphological interest as a rudiment, being homologous to the hollow
radial beams which connect the two concentric spheres of the Cannosphærida.
Possibly the Aulosphærida have been derived from the latter by loss of the
inner shell and reduction of the radial beams; the centripetal beams which
are found in many (but not in all) Aulosphærida, may be the last remnant of
those radial beams. They contain also an axial filament, as a direct
internal prolongation of that of the external radial spine. The axial
filaments of the radial spines are usually connected with their thin wall
by a variable number of scattered transverse threads, or sometimes even by
thin transverse septa (Pl. 110, figs. 4-7, &c.). This structure corresponds
to the similar axial filaments and their thin filiform transverse branches
which we have found in other PHÆODARIA, _e.g._, in the Tuscarorida and
Circoporida.
The Aulonida (with polygonal meshes) exhibit in general the same structure
as the Aularida (with triangular meshes). But whilst in the latter usually
six tangential tubes are united at each nodal point, in the former only
three or four tubes become united. Therefore also the number of the small
sutural partitions or astral septa, which radiate from the central openings
of the nodal cavity, is six in the latter, three or four in the former.
Correspondingly three or four small pores lead from the nodal cavity into
the surrounding tangential tubes.
The true nature of the nodal points, and the intimate structure of the
different parts here united, is a matter which it is very difficult to
explain. It is a certain fact, well established by hundreds of
observations, that in the complete and well-preserved skeletons which are
perfectly purified by fire, or by hot mineral acids, and afterwards dried,
all the tubes of the skeleton, the tangential as well as the radial
cylinders, become filled up by air. Each tube contains usually one large
cylindrical air-bubble, with two hemispherical ends. But the air-bubbles of
the neighbouring tubes are completely separated one from another by the
thin astral or sutural septa, and the air-bubble of the radial tubes is
also separated from the former. The central cavity of each nodal point is
therefore surrounded in the Aularida by six, in the Aulonida by three or
four separate cylinders of air. This fact seems to be explained only on the
supposition that each single tube has two terminal pores or fissures, which
open into the two nodal cavities on its two ends. The radial tubes must
also possess at least one small opening, probably on their base, and
probably they have another on their distal apex. In no other way can it be
explained, that in all complete, well-preserved and purified skeletons,
each single tube constantly becomes easily filled by an air-bubble after
drying.
In the living Aulosphærida the cavities of all tubes are filled up by a
jelly-substance, {1619}which may be stained by carmine and is probably
identical with the jelly of the calymma. The latter is probably in direct
connection with the former by the central pore of the nodal cavity, which
is placed on its inside and surrounded by the astral septa; these separate
the tangential tubes, radiating from one nodal point, completely, and are
thin and simple, but very solid lamellæ of silica. Therefore the nodal
stars of broken shells usually remain united, whilst the single radiating
tubes composing them are broken off (Pl. 110, figs. 3, 8, 10). But it
happens only rarely (and only in certain individual species) that complete
single tubes separate; usually the fragments of the connected neighbouring
tubes remain on their ends. The two small terminal openings of each
tangential tube, which lead from its cavity into the nodal cavity, and are
surrounded on each end by the truncated ends of two neighbouring astral
septa, are very difficult to observe (Pl. 110, figs. 8-10).
The wonderful elegance and the high complication of these regular skeletons
of the Aulosphærida, produced by a single cell, becomes increased by the
graceful and manifold appendages and apophyses which are usually developed
on the radial tubes. In only a few species these are simple, as in the
common and cosmopolitan _Aulosphæra trigonopa_. Usually lateral or terminal
appendages are developed in great variety, a selection of which is figured
in Pls. 109-111. The lateral branches are either irregularly scattered
spines (Pl. 110, figs. 3-7) or regular verticils of cruciate or radiate
spines; each verticil is usually composed of four perpendicularly crossed
horizontal branches (Pl. 109, figs. 3, 4, 7, 10, &c.), more rarely of a
greater number of radiating transverse branches.
The terminal appendages of the radial spines exhibit a striking similarity
with those of the Aulacanthida (Pls. 102-105). They are either forks with
two or three divergent branches (Pl. 111, figs. 3, 4), or regular crosses
with four branches opposite in pairs (Pl. 109, figs. 2, 6, 7, 10), or
elegant crowns or verticils, composed of numerous radiating branches (Pl.
110, figs. 1-6). The distal ends of the terminal as well as of the lateral
branches are either simple, pointed, or armed with a spinulate knob, or
with a terminal spathilla. The variety and elegance of these terminal
ornaments, the function of which is that of capturing tentacles, is in the
Aulosphærida not less admirable than in the Aulacanthida and Coelodendrida.
The _central capsule_ of the Aulosphærida (Pl. 111, fig. 2) was first
figured in my Monograph (1862, Taf. xi. fig. 5) of _Aulosphæra
elegantissima_, as a sphere of 0.2 to 0.3 mm. in diameter. I described
there the large nucleus (of half that size) as a spherical "Binnenblase,"
and the numerous pseudopodia which arise from the capsule and radiate
through the meshes of the lattice-shell. But I had not observed at that
time the three typical openings of the capsule, which were first discovered
and accurately described by R. Hertwig (1879, _loc. cit._, p. 94, Taf. x.
figs. 2, 4, 5, 8, 14). The large astropyle with its radiate operculum and
proboscis, and the two smaller lateral parapylæ, provided with {1620}a
smaller tubule, have in general the same shape as in the closely allied
Sagosphærida and Orosphærida, and agree in their strong development with
that of the Aulacanthida. The collection of the Challenger contains
numerous well-preserved preparations of Aulosphærida, which were stained by
carmine immediately after being captured, and in which the central capsule
and its nucleus exhibit the same intimate structure already accurately
described by R. Hertwig. The diameter of the capsule is usually between 0.2
and 0.3, rarely less than 0.15 or more than 0.35 mm., the nucleus has half
that size. The phæodium has usually about the same volume (Pl. 109, fig.
1), but seems to be in many Aulosphærida less developed than in the other
PHÆODARIA.
_Synopsis of the Genera of Aulosphærida._
-------------------------------------------------------------------------
I. Subfamily Aularida.
Meshes of the network triangular, regular or subregular. Six
tangential tubes united at each nodal point of the net.
-------------------------------------------------------------------------
{ Without radial tubes, 682. _Aularia_.
Shell spherical, with {
a simple network. { With radial tubes in
{ the nodes of the net, 683. _Aulosphæra_.
{ Shell covered with pyramidal
{ elevations, the top of
Shell spherical, with { which bears a radial tube, 684. _Auloscena_.
pyramidal elevations {
or with spongy { Shell with spongy framework,
framework. { the surface of which bears
{ radial tubes, 685. _Auloplegma_.
{ Shell lenticular, with
Shell not spherical, { shortened main axis and
either lenticular or { radial tubes, 686. _Aulophacus_.
spindle-shaped, with {
simple network. { Shell spindle-shaped, with
{ prolonged main axis and
{ radial tubes, 687. _Aulatractus_.
-------------------------------------------------------------------------
II. Subfamily Aulonida.
Meshes of the network polygonal, usually irregular. Three or four
(rarely more) tangential tubes united at each nodal point.
-------------------------------------------------------------------------
{ Without radial tubes, 688. _Aulonia_.
Shell spherical, with {
a simple network. { With radial tubes in the
{ nodes of the net, 689. _Aulastrum_.
Shell spherical, with { Without radial tubes, 690. _Aulodictyum_.
a spongy framework. {
Subfamily 1. AULARIDA, Haeckel.
_Definition._--Network of the shell with triangular, regular or subregular
meshes; six tangential tubes being united at each nodal point.
{1621}Genus 682. _Aularia_,[301] n. gen.
_Definition._--#Aulosphærida# with triangular meshes in the network, the
tangential tubes of which form a simple smooth lattice-sphere. No radial
tubes at the nodal points.
The genus _Aularia_ is the simplest form of the subfamily Aularida, or of
those Aulosphærida in which the network of the shell is composed of regular
or subregular triangular meshes; they are the main group of the family,
much more common and far richer in distinct forms than the Aulonida (or the
Aulosphærida with polygonal meshes). The shell of _Aularia_, the probable
ancestral form of the family, is a simple lattice-sphere with smooth
surface, and differs from the common _Aulosphæra_ in the absence of radial
tubes, arising at the nodal points.
1. _Aularia ternaria_, n. sp. (Pl. 111, fig. 2).
Tangential tubes of the network cylindrical, straight, smooth, of equal
breadth. Triangular meshes of the reticular sphere very regular,
equilateral triangular. This species is the simplest of all Aulosphærida
and similar to the common _Aulosphæra trigonopa_, but has no radial tubes.
_Dimensions._--Diameter of the sphere 1.0 to 2.0; tubes 0.1 to 0.15 long,
0.007 to 0.01 broad.
_Habitat._--Central Pacific, Stations 270 to 274, surface.
2. _Aularia tubularia_, n. sp.
Tangential tubes of the network cylindrical, straight, of equal breadth,
thorny, covered with numerous short bristle-shaped thorns, which are all of
the same length and perpendicular to the tube.
_Dimensions._--Diameter of the sphere 3.0; tubes 0.15 long, 0.005 broad.
_Habitat._--South Pacific, Station 291, depth 2250 fathoms.
3. _Aularia trigonaria_, n. sp.
Tangential tubes of the network smooth, very thin in the middle part,
gradually dilated towards both ends, so that the nodal points of the
network are inflated. (Similar to _Aulosphæra sceptrophora_, Pl. 109, fig.
3, but without radial tubes.)
_Dimensions._--Diameter of the sphere 2.2; tubes 0.1 long, 0.002 broad in
the middle part, 0.01 on both sides.
_Habitat._--North Pacific, Station 253, depth 3125 fathoms.
{1622}Genus 683. _Aulosphæra_,[302] Haeckel, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 802.
_Definition._--#Aulosphærida# with triangular meshes in the network, the
tangential tubes of which form a simple lattice-sphere. Radial tubes arise
at its nodal points.
The genus _Aulosphæra_, the first observed form of all Aulosphærida, is
also the most common form of the whole family, the richest in distinct
species, and widely distributed over all oceans, in the tropical as well as
in the temperate and Arctic zones.
The twenty-one species here enumerated may be only a small part of the
numerous forms, which may be distinguished according to the different forms
of the tubes. One of the two Mediterranean species, which I first described
in my Monograph, is cosmopolitan. The shell is in all species a simple
regular lattice-sphere with triangular meshes; it differs from the
preceding _Aularia_ in the development of radial tubes at the nodal points
of the lattice-work.
Subgenus 1. _Aulosphærantha_, Haeckel.
_Definition._--Radial tubes simple, smooth, without terminal teeth and
without lateral branches.
1. _Aulosphæra trigonopa_, Haeckel.
_Aulosphæra trigonopa_, Haeckel, 1862, Monogr. d. Radiol., p. 359, Taf.
x. fig. 4.
Radial tubes of the spherical shell cylindro-conical, straight, smooth, of
the same length as the tangential tubes of the network, which are also
smooth, straight, cylindrical.
_Dimensions._--Diameter of the sphere 1.0 to 2.0; tangential tubes 0.1 to
0.2 long, 0.002 to 0.004 broad.
_Habitat._--Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific,
surface.
2. _Aulosphæra flexuosa_, n. sp.
Radial tubes slenderly conical, smooth, gradually tapering towards the
distal end, more or less irregularly curved, two to three times as long as
the tangential tubes, which are cylindrical, straight and smooth.
_Dimensions._--Diameter of the sphere 2.2; tangential tubes 0.15 long,
0.006 broad.
_Habitat._--North Atlantic, Færöe Channel (Gulf Stream), John Murray,
surface.
{1623}Subgenus 2. _Aulosphærella_, Haeckel.
_Definition._--Radial tubes smooth, without lateral branches or spines, but
armed with a verticil of teeth at the distal end.
3. _Aulosphæra diodon_, n. sp.
Radial tubes cylindro-conical, straight, smooth, of the same length as the
smooth, cylindrical, tangential tubes; armed at the distal end with two
divergent terminal teeth, which are slightly curved, pincer-shaped, and
about one-fourth as long as the tube.
_Dimensions._--Diameter of the sphere 2.5; tangential tubes 0.16 long,
0.003 broad.
_Habitat._--South Atlantic, Station 332, depth 2200 fathoms.
4. _Aulosphæra triodon_, n. sp. (Pl. 109, fig. 8).
Radial tubes cylindrical, straight, smooth, two to three times as long as
the smooth, cylindrical, tangential tubes; armed at the distal end with
three divergent terminal teeth, which are straight or slightly curved and
about one-third as long as the tube.
_Dimensions._--Diameter of the sphere 1.2; tangential tubes 0.1 long, 0.01
broad.
_Habitat._--North-Eastern Pacific (off Japan), Station 231, surface.
5. _Aulosphæra tetrodon_, n. sp.
Radial tubes slender, cylindrical, straight, smooth, about three times as
long as the smooth, cylindrical, tangential tubes; armed at the distal end
with a regular cross of four terminal teeth, which are directed almost
horizontally, and are slightly recurved (just as in _Aulosphæra
spathillata_, Pl. 109, fig. 7, but longer and without lateral verticils).
_Dimensions._--Diameter of the sphere 1.6; tangential tubes 0.15 long,
0.005 broad.
_Habitat._--South Pacific, Station 289, depth 2550 fathoms.
6. _Aulosphæra polyodon_, n. sp.
Radial tubes slender, spindle-shaped, gradually tapering towards the two
ends, smooth, about twice as long as the cylindrical, smooth, tangential
tubes; armed at the distal end with a verticil of twelve to twenty or more
divergent, conical, slightly curved teeth.
_Dimensions._--Diameter of the sphere 3.3; tangential tubes 0.2 long, 0.01
broad.
_Habitat._--Central Pacific, Station 272, depth 2600 fathoms.
Subgenus 3. _Aulosphærissa_, Haeckel.
_Definition._--Radial tubes verticillate, armed with a variable number of
regular verticils of lateral branches.
{1624}7. _Aulosphæra verticillata_, n. sp.
Radial tubes slender, cylindro-conical, straight, tapering towards the
distal end, about as long as the smooth, cylindrical, tangential tubes;
armed with eight to twelve verticils of three curved, simple, lateral
branches. (Very similar to the tubes of _Aulastrum trichoceros_, Pl. 111,
fig. 5_a._)
_Dimensions._--Diameter of the sphere 1.6; tangential tubes 0.15 long,
0.008 broad.
_Habitat._--South Pacific, Station 300, surface.
8. _Aulosphæra spathillata_, n. sp. (Pl. 109, figs. 7, 7_a_).
Radial tubes slender, cylindro-conical, straight, tapering towards the
distal end, two to three times as long as the smooth, cylindrical,
tangential tubes; armed with two or three distal alternate verticils, each
of which forms a horizontal cross of four (sometimes three or five)
equidistant branches; their distal ends are on the terminal cross simple
hooks, on the proximal cross spathillæ.
_Dimensions._--Diameter of the sphere 3.2; tangential tubes 0.12 to 0.16
long, 0.01 broad.
_Habitat._--South-Eastern Pacific (off Valparaiso), Station 298, depth 2225
fathoms.
9. _Aulosphæra cruciata_, Haeckel (Pl. 109, fig. 10).
_Aulosphæra elegantissima_, R. Hertwig (_non_ Haeckel), 1879, Organism.
d. Radiol., p. 90, Taf. ix. fig. 1; Taf. x. figs. 2, 4, 5, 8, 14, 15.
? _Aulosphæra pourtalesii_, Duncan, 1881, Journ. Roy. Micr. Soc., p. 175,
pl. iii. figs. 1-3.
Radial tubes slender, cylindro-conical, straight, tapering towards the
distal end, twice as long as the smooth, cylindrical, tangential tubes;
armed with four to eight cruciate equidistant verticils, each of which
forms a regular cross of four equal, horizontal, lateral branches, bearing
at the end a small knob or spathilla.
_Dimensions._--Diameter of the sphere 1.2 to 1.8; tangential tubes 0.1 to
0.15 long, 0.003 broad.
_Habitat._--Mediterranean (Messina), North Atlantic (Canary Islands),
Caribbean Sea.
10. _Aulosphæra elegantissima_, Haeckel.
_Aulosphæra elegantissima_, Haeckel, 1862, Monogr. d. Radiol., p. 359,
Taf. x. fig. 5; Taf. xi. figs. 5, 6.
Radial tubes cylindrical, straight, twice as long as the smooth,
cylindrical, tangential tubes; armed with four to eight equidistant
verticils, each of which is composed of eight to twelve simple, horizontal,
lateral branches.
_Dimensions._--Diameter of the sphere 1.5 to 2; tangential tubes 0.12 to
0.16 long, 0.004 broad.
_Habitat._--Mediterranean (Messina), surface.
11. _Aulosphæra bisternaria_, n. sp. (Pl. 109, figs. 11, 12).
Radial tubes cylindrical, straight, about as long as the cylindrical
tangential tubes, smooth or somewhat thorny, armed at the distal end with
two alternate verticils of three branches, which bear {1625}a terminal
spathilla; the proximal branches are twice as long as the distal, and
alternate with them regularly, so that the six branches lie in six
different meridional planes.
_Dimensions._--Diameter of the sphere 2.5; tangential tubes 0.2 long, 0.01
broad.
_Habitat._--Antarctic Ocean, Station 156, surface.
12. _Aulosphæra dendrophora_, n. sp. (Pl. 109, figs. 1, 2).
Radial tubes cylindrical, straight, about as long as the cylindrical,
smooth, tangential tubes, armed in the distal half with three verticils of
four crossed branches; the four proximal branches are three times as long
as the four distal, and twice as long as the four intermediate branches.
All twelve branches bear a terminal spinulate knob, and lie in two
perpendicularly crossed meridian planes.
_Dimensions._--Diameter of the sphere 2.2 to 2.8; tangential tubes 0.2
long, 0.01 broad.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
13. _Aulosphæra sceptrophora_, n. sp. (Pl. 109, figs. 3, 4).
Radial tubes straight, in the proximal half conical, with inflated base; in
the distal half cylindrical, with five or six cruciate verticils, each of
which has four perpendicularly crossed teeth. Tangential tubes half as long
as the radial tubes, in the middle part very thin, thickened towards both
ends.
_Dimensions._--Diameter of the sphere 1.2; tangential tubes 0.1 long, 0.002
broad in the middle part, 0.012 on both ends.
_Habitat._--Central Pacific, Station 266, depth 2750 fathoms.
14. _Aulosphæra spathophora_, n. sp.
Radial tubes slender, cylindrical, more or less curved, about three times
as long as the tangential tubes, in the distal half with eight to twelve
verticils of six to eight lateral branches, which are forked, decrease in
length towards the distal end, and bear on each ramule a terminal
spathilla. Tangential tubes slightly curved and thorny. (Similar to
_Auloplegma perplexum_, Pl. 111, fig. 8_a_, but with a simple
lattice-sphere.)
_Dimensions._--Diameter of the sphere 2.2; tangential tubes 0.2 long. 0.006
broad.
_Habitat._--North Pacific, Station 244, depth 2900 fathoms.
Subgenus 4. _Aulosphæromma_, Haeckel.
_Definition._--Radial tubes spiny or thorny, with irregular lateral
branches, often with forked distal ends.
{1626}15. _Aulosphæra bifurca_, n. sp.
Radial tubes cylindrical, straight, thorny, twice as long as the smooth,
cylindrical, tangential tubes, forked at the distal end, with two curved,
convergent, thorny, terminal branches. (Similar to _Aulastrum dendroceros_,
Pl. 111, figs. 4_a_-4_c_, but with longer and more spinulate branches.)
_Dimensions._--Diameter of the sphere 3.2; tangential tubes 0.25 long, 0.01
broad.
_Habitat._--North Pacific, Station 239, surface.
16. _Aulosphæra trifurca_, n. sp. (Pl. 109, fig. 9).
Radial tubes cylindrical, straight, thorny, about as long as the smooth,
cylindrical, tangential tubes, forked at the distal end, with three curved,
convergent, terminal branches.
_Dimensions._--Diameter of the sphere 2.5 to 3.0; tangential tubes 0.2
long, 0.01 broad.
_Habitat._--North Pacific, Station 240, surface.
17. _Aulosphæra quadrifurca_, n. sp.
Radial tubes cylindro-conical, straight, about as long as the smooth,
cylindrical, tangential tubes; studded with numerous irregular lateral
branches in the distal half, and armed at the distal end with a cross of
four divergent, forked, terminal branches.
_Dimensions._--Diameter of the sphere 4.2; tangential tubes 0.2 long, 0.01
broad.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface.
18. _Aulosphæra multifurca_, n. sp.
Radial tubes cylindrical, more or less curved, three to four times as long
as the smooth, often curved, tangential tubes; studded with numerous
forked, irregular, lateral branches, and armed at the distal end with a
verticil of twelve to sixteen divergent, forked, terminal branches.
_Dimensions._--Diameter of the sphere 1.2; tangential tubes 0.06 long,
0.003 broad.
_Habitat._--Arctic Ocean, Greenland (Olrik), surface.
19. _Aulosphæra coronata_, n. sp.
Radial tubes spindle-shaped, tapering from the thicker middle part towards
both ends, twice as long as the thorny tangential tubes, studded with
numerous irregular, curved, lateral spines, and bearing at the distal end a
corona of twenty to twenty-five divergent, curved, terminal branches.
(Similar to _Auloscena flammabunda_, Pl. 110, fig. 4.)
_Dimensions._--Diameter of the sphere 3.0; tangential tubes 0.2 long, 0.08
broad.
_Habitat._--Tropical Atlantic, Station 347, surface.
{1627}20. _Aulosphæra undulata_, n. sp. (Pl. 109, fig. 6).
Radial tubes slender, cylindro-conical, undulate, about twice as long as
the spinulate and undulate tangential tubes; studded with numerous short,
perpendicular, lateral branches which are partly simple, partly forked, and
bear small terminal spathillæ. The distal end of each radial tube bears
usually a verticil of four to eight similar pediculate spathillæ.
_Dimensions._--Diameter of the sphere 2.4; tangential tubes 0.2 long, 0.005
broad.
_Habitat._--North Pacific, Station 252, surface.
21. _Aulosphæra spinosa_, n. sp. (Pl. 109, fig. 5).
Radial tubes and tangential tubes equal in size and similar in form, more
or less curved, slender, cylindrical, densely studded with numerous
irregular spines.
_Dimensions._--Diameter of the sphere 1.6; tangential tubes 0.1 long, 0.004
broad.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
Genus 684. _Auloscena_,[303] n. gen.
_Definition._--#Aulosphærida# with triangular meshes in the network, the
tangential tubes of which arise in pyramidal groups of six over the surface
of the spherical shell. Radial tubes arise at the tops of the six-sided
pyramids, which cover the whole surface.
The genus _Auloscena_ differs from the preceding _Aulosphæra_, its
ancestral form, in a very remarkable and elegant character. The tangential
tubes of the network here lie not on a spherical face (as in the latter),
but arise over the surface of the spherical calymma in the form of
numerous, regular, hexagonal pyramids; each pyramid being composed of six
convergent ascending tubes, which are united in a common nodal point; at
the latter arises a radial tube, which usually bears an elegant corona of
radially divergent terminal branches. Therefore the base of each hexagonal
pyramid is in contact at its six corners with the basal corners of six
similar neighbouring pyramids, whilst the neighbouring sides of the bases
are separated by six regular triangular meshes, which lie on the spherical
face. In some species this remarkable and elegant structure is quite
regular, whilst in others it becomes more or less irregular.
Subgenus 1. _Auloscenium_, Haeckel.
_Definition._--Radial tubes smooth, without lateral branches or spines,
bearing a terminal verticil at the distal end.
{1628}1. _Auloscena mirabilis_, n. sp. (Pl. 110, figs. 1, 2).
Radial tubes cylindrical, straight, smooth, about as long as the smooth
pyramidal tubes (or the convergent tubes which form the edges of the
six-sided pyramids of the network). The distal end of each radial tube
bears an elegant spathillate terminal corona (fig. 2), or a verticil of
fifteen to twenty curved radial branches, the distal end of which is armed
with a spinulate knob.
_Dimensions._--Diameter of the sphere 2.0 to 3.0; pyramidal tubes 0.16 to
0.24 long, 0.008 broad.
_Habitat._--Central Pacific, Stations 271 to 274, depth 2350 to 2750
fathoms.
2. _Auloscena spectabilis_, n. sp. (Pl. 110, figs. 8, 9).
Radial tubes cylindro-conical, straight, smooth, twice as long as the
smooth pyramidal tubes, armed at the distal end with a conical terminal
corona, or a verticil of twelve to sixteen divergent, straight, pointed,
terminal branches.
_Dimensions._--Diameter of the sphere 4.0 to 5.0; pyramidal tubes 0.25 to
0.3 long, 0.012 broad.
_Habitat._--Antarctic Ocean, Station 154, surface.
3. _Auloscena pyramidalis_, n. sp.
Radial tubes slender, conical, straight, smooth, of the same length as the
smooth pyramidal tubes, armed at the distal end with a hexagonal terminal
corona, or a verticil of six divergent, straight, pointed, terminal
branches, which correspond to the six sides of a pyramid; the proximal apex
of this terminal pyramid is opposed to the distal apex of the similar basal
pyramid.
_Dimensions._--Diameter of the sphere 3.0 to 4.0; pyramidal tubes 0.2 to
0.3 long, 0.01 broad.
_Habitat._--Tropical Atlantic, Stations 347 to 349, surface.
Subgenus 2. _Auloscenidium_, Haeckel.
_Definition._--Radial tubes thorny, with lateral branches or spines,
usually with a terminal verticil at the distal end.
4. _Auloscena tentorium_, n. sp. (Pl. 110, fig. 6).
Radial tubes spindle-shaped, tapering towards both ends, nearly smooth, of
the same length as the smooth pyramidal tubes. The distal part of the
radial tubes is thorny, and bears a verticil or a corona of twenty to
thirty slender terminal branches, which are about one-third as long as the
tube, sabre-shaped, with concave outer edge and pointed distal end.
_Dimensions._--Diameter of the sphere 4.0; radial tubes 0.3 to 0.4 long,
0.02 to 0.03 broad.
_Habitat._--North-Western Pacific (off Japan), Station 231, surface.
{1629}5. _Auloscena verticillus_, n. sp. (Pl. 110, figs. 10, 11).
Radial tubes slender, cylindrical, twice as long as the smooth or somewhat
thorny pyramidal tubes, armed in the distal part with two or three
irregular verticils of three to six perpendicular spines, and on the distal
end with a corona of twelve to eighteen straight, divergent, pointed,
terminal branches, which often arise in pairs.
_Dimensions._--Diameter of the sphere 3.2; pyramidal tubes 0.15 long, 0.01
broad.
_Habitat._--South Atlantic, Station 318, depth 2040 fathoms.
6. _Auloscena penicillus_, n. sp. (Pl. 110, fig. 3).
Radial tubes slender, cylindrical, thorny, one and a half times as long as
the thin and smooth pyramidal tubes, armed in the distal half with densely
crowded perpendicular spines and a terminal corona of numerous (twenty to
thirty or more) bristle-shaped branches, like a brush.
_Dimensions._--Diameter of the sphere 2.0 to 2.5; radial tubes 0.15 to 0.2
long, 0.005 to 0.01 broad.
_Habitat._--Antarctic Ocean, Stations 156, 157, surface.
7. _Auloscena flammabunda_, n. sp. (Pl. 110, fig. 4).
Radial tubes cylindro-conical, twice as long as the thorny pyramidal tubes,
studded with numerous curved spines, and armed with a verticil or corona of
numerous (twenty to thirty or more) undulate, divergent, pointed, terminal
branches.
_Dimensions._--Diameter of the sphere 3.0; radial tubes 0.3 to 0.4 long,
0.02 to 0.03 broad.
_Habitat._--North Pacific, Station 252, surface.
8. _Auloscena gigantea_, n. sp. (Pl. 110, fig. 7).
Radial tubes cylindrical, thorny, about as long as the thorny pyramidal
tubes, armed in the distal half with four to eight verticils of short
curved ciliæ, and at the distal end with a similar small terminal verticil.
_Dimensions._--Diameter of the sphere 5.2; pyramidal tubes 0.2 to 0.3 long,
0.01 broad.
_Habitat._--Central Pacific, Stations 265 to 268, surface.
9. _Auloscena arboretum_, n. sp.
Radial tubes cylindrical, straight or slightly curved, about the same
length as the smooth pyramidal tubes; armed in the distal half with three
or four verticils, tapering in size towards the distal end; each verticil
is composed of four crossed and curved branches, which bear a terminal
spinulate knob. (This species is very similar to _Aulosphæra dendrophora_,
Pl. 109, fig. 1, and may {1630}be derived from it by elevation of the
hexagonal pyramids, which in the latter lie in the spherical plane).
_Dimensions._--Diameter of the sphere 4.4; pyramidal tubes 0.25 long, 0.01
broad.
_Habitat._--Indian Ocean, Cocos Islands (Rabbe), surface.
10. _Auloscena serrata_, n. sp. (Pl. 110, fig. 5).
Radial tubes spindle-shaped, tapering towards both ends, thorny, twice as
long as the thorny pyramidal tubes; armed at the distal end with an elegant
corona which is composed of twelve to sixteen curved terminal branches.
Each branch bears two opposite series of small recurved teeth and a
terminal spathilla of six to eight larger recurved teeth.
_Dimensions._--Diameter of the sphere 3.0; pyramidal tubes 0.3 long, 0.012
broad.
_Habitat._--South Pacific, Station 298, depth 2225 fathoms.
Genus 685. _Auloplegma_,[304] Haeckel, 1879, Sitzungsb. med.-nat.
Gesellsch. Jena, Dec. 12, p. 6.
_Definition._--#Aulosphærida# with triangular meshes in the network, the
tubes of which are connected in different directions, and form the spongy
wall of a spherical shell. Radial tubes arise on the surface at the nodal
points.
The genus _Auloplegma_, one of the rarest forms of Aulosphærida, differs
from the preceding genera in the spongy structure of the lattice-sphere,
the thickened wall of which is composed of a loose framework. Numerous
tubes, irregularly disposed in different directions, are connected at the
nodal points of this loose spongy framework, whilst radial tubes arise on
the surface of the latter. _Auloplegma_ exhibits therefore a relation to
_Aulosphæra_, its probable ancestral form, similar to that which
_Plegmosphæra_ does to _Acanthosphæra_ among the #Sphæroidea#.
1. _Auloplegma perplexum_, n. sp. (Pl. 111, figs. 8, 8_a_).
Radial tubes straight, cylindro-conical, armed with six to eight verticils
of lateral branches, which increase in size towards the base; each verticil
is a cross of four dichotomous delicate ramules, ending with a spinulate
knob. The length of the radial tube is about equal to the radial diameter
of the spongy framework, which forms the thick wall of the spherical shell,
and is composed of smooth and straight cylindrical tubes.
_Dimensions._--Diameter of the shell 1.5 to 2.0, of its wall 0.3 to 0.4;
length of the radial tubes 0.2 to 0.3, basal breadth 0.015.
_Habitat._--North Pacific, Station 237, surface.
{1631}2. _Auloplegma spongiosum_, n. sp. (Pl. 111, fig. 9).
Radial tubes slender, straight, cylindro-conical, studded irregularly with
lateral branches, which are short, simple, slightly curved, partly
verticillate in the distal third, and ending with a small spinulate knob.
The length of the radial tubes is about twice as great as the radial
diameter of the spongy framework, which forms the wall of the spherical
shell, and is composed of thorny or verticillate cylindrical tubes.
_Dimensions._--Diameter of the shell 3.2, of its wall 0.1; length of the
radial tubes 0.24, breadth 0.01.
_Habitat._--North Pacific, Station 231, surface.
Genus 686. _Aulophacus_,[305] n. gen.
_Definition._--#Aulosphærida# with triangular meshes in the network, the
tangential tubes of which form a simple, lenticular, biconvex
lattice-shell, with shortened vertical main axis. Radial tubes arise at its
nodal points.
The genus _Aulophacus_ differs from the common _Aulosphæra_, its ancestral
form, only in the lenticular compression of the spherical lattice-shell,
the vertical axis of which is considerably shortened. It exhibits therefore
to the latter the same relation as _Cenodiscus_ does to _Cenosphæra_ among
the #Sphæroidea#. The contrary condition is shown in the following genus
_Aulatractus_, in which the vertical axis is prolonged. In the two species
of _Aulophacus_ observed the radial spines exhibit a remarkable
peculiarity, being longer on the circular periphery of the lens, shorter on
both its faces, and shortest in the vertical main axis.
1. _Aulophacus lenticularis_, n. sp. (Pl. 111, fig. 5_a_).
Shell biconvex, lenticular, with rounded circular margin; its horizontal
diameter three times as great as its thickness (or its vertical main axis).
Radial tubes cylindro-conical, straight, with six to nine triradiate
verticils, those of the margin of the lens twice as long as the smooth
tangential tubes, the others shorter.
_Dimensions._--Horizontal diameter of the lens 5.5 mm., vertical main axis
0.2; length of the radial tubes 0.2, breadth 0.01.
_Habitat._--Indian Ocean, Belligemma, Ceylon (Haeckel), surface.
2. _Aulophacus amphidiscus_, n. sp. (Pl. 111, fig. 5_b_).
Shell discoidal, slightly biconvex, with rounded circular margin; its
horizontal diameter five times as great as its thickness. Radial tubes
cylindrical, covered with numerous short thorns, those of the margin of the
lens three times as long as the smooth tangential tubes, the others
shorter.
{1632}_Dimensions._--Horizontal diameter of the lens 6.0, vertical main
axis 1.2; length of the radial tubes 0.2, breadth 0.005.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface.
Genus 687. _Aulatractus_,[306] n. gen.
_Definition._--#Aulosphærida# with triangular meshes in the network, the
tangential tubes of which form an ellipsoidal or spindle-shaped, simple
lattice-shell, with prolonged vertical main axis. Radial tubes arise at its
nodal points.
The genus _Aulatractus_ differs from all the other Aulosphærida in the
peculiar prolongation of the vertical axis of the lattice-sphere, by which
the latter becomes ellipsoidal or spindle-shaped. The triangular meshes of
the regular lattice-work become usually more or less irregular and
polygonal at the two poles of the elongated main axis. _Aulatractus_ seems
to be developed from _Aulosphæra_ in the opposite way from _Aulophacus_,
the former by elongating, the latter by shortening of the vertical
main-axis.
1. _Aulatractus fusiformis_, n. sp. (Pl. 111, figs. 6, 6_a_, 6_b_).
Shell spindle-shaped, about twice as long as broad, rounded at both poles
of the main axis. Tangential tubes smooth, cylindrical. Radial tubes of the
same length as the tangential tubes, but much thinner, slender cylindrical,
studded with perpendicularly arising, short, lateral branches, which are
scattered in the proximal part, verticillate in the distal part, and bear a
spinulate terminal knob.
_Dimensions._--Length of the shell 7.5 to 10.0, breadth 3.5; length of the
radial tubes 0.15 to 0.18, breadth 0.004.
_Habitat._--Tropical Atlantic, Stations 348, 349; surface, and in various
depths.
2. _Aulatractus diploconus_, n. sp. (Pl. 111, fig. 7).
Shell diploconical or nearly spindle-shaped, about three times as long as
broad, equally pointed at the two poles of the main axis, not inflated in
the middle part. Radial tubes slenderly conical, thorny, only half as long
as the smooth tangential tubes.
_Dimensions._--Length of the shell 6.0 to 8.0, breadth 2.2 to 4.5; length
of the radial tubes 0.1 to 0.15, breadth 0.007.
_Habitat._--North Atlantic, Canary Islands, Station 353, surface.
3. _Aulatractus fusulus_, n. sp.
Shell spindle-shaped, about twice as long as broad, pointed at the two
equal poles of the main axis. Radial tubes cylindro-conical, smooth, about
as long as the smooth tangential tubes. This {1633}species resembles in its
simple structure the common cosmopolitan _Aulosphæra trigonopa_, and
differs from it only in the constant spindle-form of the shell.
_Dimensions._--Length of the shell 6 to 8, breadth 3 to 4; length of the
radial tubes 0.16 to 0.2, breadth 0.008.
_Habitat._--North Atlantic, Færöe Channel, Gulf Stream (John Murray);
Hebrides (Moebius).
4. _Aulatractus ellipsoides_, n. sp.
Shell ellipsoidal, about twice as long as broad, with equally rounded poles
on the main axis. Radial tubes straight, cylindrical, verticillate, about
twice as long as the smooth tangential bars; each verticil is cruciate,
composed of four rectangularly crossed, short, lateral branches which bear
a small spathilla at the distal end.
_Dimensions._--Length of the shell 6.6, breadth 3.6; length of the radial
tubes 0.2, breadth 0.01.
_Habitat._--South Atlantic, Station 332, surface.
Subfamily 2. AULONIDA, Haeckel.
_Definition._--Network of the shell with polygonal, usually irregular
meshes; three or four tangential tubes usually being united at each nodal
point.
Genus 688. _Aulonia_,[307] n. gen.
_Definition._--#Aulosphærida# with polygonal meshes in the network, the
tangential tubes of which form a simple smooth lattice-sphere. No radial
tubes at the nodal points.
The genus _Aulonia_ is the simplest form of the subfamily Aulonida, or of
those Aulosphærida in which the lattice-work of the shell is composed not
of triangular but of polygonal meshes; all these Aulonida are much rarer
and much less differentiated than the Aularida or the common Aulosphærida
with triangular meshes. _Aulonia_ has the same simple, smooth, spherical
lattice-shell as _Aularia_, and differs from it only in the polygonal form
of the meshes, which, however, is very constant.
1. _Aulonia tetragonia_, n. sp.
Meshes regular or subregular, square, sometimes intermingled with a
variable number of irregular, triangular, and pentagonal meshes. Bars
cylindrical, of equal breadth.
_Dimensions._--Diameter of the spherical shell 2.0 to 3.2, of the meshes
0.12 to 0.18; breadth of the bars 0.008.
_Habitat._--Antarctic Ocean, Station 154, depth 1800 fathoms.
{1634}2. _Aulonia pentagonia_, n. sp.
Meshes subregular, pentagonal, intermingled with a smaller number of
quadrangular and triangular irregular meshes. Bars cylindrical, of equal
breadth.
_Dimensions._--Diameter of the spherical shell 2.8 to 3.2, of the meshes
0.15 to 0.2; breadth of the bars 0.01.
_Habitat._--South Pacific, Stations 293 to 302, depth 1375 to 2270 fathoms.
3. _Aulonia hexagonia_, n. sp. (Pl. 111, fig. 1).
Meshes regular or subregular, hexagonal, often intermingled with a variable
number of pentagonal and heptagonal meshes. Bars cylindrical, of equal
breadth.
_Dimensions._--Diameter of the spherical shell 2.5 to 3.3, of the meshes
0.15 to 0.25; breadth of the bars 0.012.
_Habitat._--Tropical Atlantic, Stations 347 to 349, surface.
4. _Aulonia metagonia_, n. sp.
Meshes subregularly alternating, larger octagonal and smaller tetragonal.
The network of this remarkable species has a striking similarity to the
arrangement of the radial tubes in some species of _Sycon_, figured in my
Monograph of the Calcispongiæ (1872, Bd. iii., Taf. ix. fig. 12).
_Dimensions._--Diameter of the sphere 4.4, of the greater octagonal meshes
0.24 to 0.3, smaller tetragonal 0.1 to 0.12; breadth of the bars 0.007.
_Habitat._--Indian Ocean, Cocos Islands (Rabbe), surface.
5. _Aulonia polygonia_, n. sp.
Meshes irregular, polygonal, variable in form and unequal in size; the
majority usually pentagonal or hexagonal, but numerous intermingled meshes
with three, four, seven, or eight sides. Very variable in the size of the
bars and the form of the meshes.
_Dimensions._--Diameter of the sphere 2.5 to 5.5, of the meshes 0.1 to 0.2;
breadth of the bars 0.008 to 0.12.
_Habitat._--Cosmopolitan; Atlantic, Indian, Pacific, surface.
Genus 689. _Aulastrum_,[308] n. gen.
_Definition._--#Aulosphærida# with polygonal meshes in the network, the
tangential tubes of which form a simple lattice-sphere. Radial tubes arise
at its nodal points.
{1635}The genus _Aulastrum_ differs from the preceding _Aulonia_, its
ancestral form, only in the development of radial spines at the nodal
points of the simple lattice-sphere. It exhibits therefore to the latter
the same relation as _Aulosphæra_ does to _Aularia_. But the meshes of the
spherical network are constantly triangular in the two latter genera,
polygonal in the two former. The different species of _Aulastrum_ are much
rarer, and are not so differentiated as those of the common _Aulosphæra_.
1. _Aulastrum monoceros_, n. sp.
Radial tubes simple, smooth, straight, cylindro-conical, about as long as
the smooth tangential tubes or somewhat longer. Meshes of the network
irregularly polygonal, the majority usually pentagonal or hexagonal.
_Dimensions._--Diameter of the sphere 3.0 to 4.0, of the meshes 0.15;
breadth of the tubes 0.012.
_Habitat._--Tropical Atlantic, Stations 347, 348, depth 2250 to 2450
fathoms.
2. _Aulastrum dichoceros_, n. sp.
Radial tubes cylindrical, more or less curved, undulate, smooth, twice as
long as the smooth tangential tubes, forked at the distal end, with two
divergent curved branches. Meshes of the network subregular, hexagonal (as
in _Aulonia hexagonia_, Pl. 111, fig. 1), intermingled with single
pentagonal and square meshes.
_Dimensions._--Diameter of the sphere 2.0 to 2.5, of the meshes 0.12 to
0.18; breadth of the tubes 0.01.
_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.
3. _Aulastrum dendroceros_, n. sp. (Pl. 111, figs. 4_a_, _b_, _c_).
Radial tubes cylindrical, straight or slightly curved, thorny, forked at
the distal end, two to three times as long as the thorny tangential tubes;
the thorns are short and thin, partly simple, partly irregularly branched
and scattered, arborescent. Meshes of the network irregularly polygonal,
the majority pentagonal or tetragonal.
_Dimensions._--Diameter of the sphere 2.4; radial tubes 0.2 to 0.3 long,
0.02 broad.
_Habitat._--North Pacific, Station 241 to 244, surface.
4. _Aulastrum triceros_, n. sp. (Pl. 111, figs. 3, 3_a_).
Radial tubes cylindrical, straight, smooth, about twice as long as the
smooth tangential tubes, armed with three divergent curved teeth at the
distal end. Meshes subregular, pentagonal, intermingled with a small number
of tetragonal and hexagonal meshes.
_Dimensions._--Diameter of the sphere 1.2 to 1.8; radial tubes 0.15 long,
0.01 broad.
_Habitat._--Tropical Atlantic, Station 349, depth 2450 fathoms.
{1636}5. _Aulastrum trichoceros_, n. sp.
Radial tubes slender, straight, cylindro-conical, about twice as long as
the smooth tangential tubes, armed with six to eight verticils of lateral
branches, each of which is composed of three short curved branches (similar
to those of _Aulophacus lenticularis_, Pl. 111, fig. 5_a_). Meshes
irregularly polygonal, the majority tetragonal, intermingled with
pentagonal and triangular meshes.
_Dimensions._--Diameter of the sphere 2.2; tangential tubes 0.12 long,
0.007 broad.
_Habitat._--South Pacific, Station 289, depth 2550 fathoms.
6. _Aulastrum tetraceros_, n. sp.
Radial tubes straight, cylindrical, about three times as long as the smooth
tangential meshes, armed with three to six subregular cruciate verticils of
branches, each of which is composed of four short, regularly crossed
branches, bearing at the end a spinulate knob (similar to those of
_Aulatractus fusiformis_, Pl. 111, fig, 6_b_). Meshes subregular, square,
intermingled with single pentagonal and hexagonal meshes.
_Dimensions._--Diameter of the sphere 1.5, of the meshes 0.12 to 0.16;
breadth of the bars 0.008.
_Habitat._--South Atlantic, Station 318, depth 2040 fathoms.
7. _Aulastrum pentaceros_, n. sp.
Radial tubes straight, cylindrical, smooth, about as long as the smooth
tangential tubes, armed at the distal end with a corona of five curved
teeth (of the same shape as in _Cannosphæra atlantica_, Pl. 112, fig. 6).
Meshes subregular pentagonal (intermingled with single tetragonal,
hexagonal, and heptagonal meshes).
_Dimensions._--Diameter of the sphere 5.0, of the meshes 0.2; breadth of
the bars 0.015.
_Habitat._--Indian Ocean, Madagascar (Rabbe), surface.
8. _Aulastrum polyceros_, n. sp.
Radial tubes spindle-shaped, tapering from the broader middle towards both
ends, spiny, twice as long as the spiny tangential tubes, armed at the
distal end with a corona of twelve to twenty divergent curved teeth
(similar to the radial tubes of _Auloscena tentorium_, Pl. 110, fig. 6).
Meshes irregular, polygonal, very variable in size and form. All tubes of
this species are armed with scattered, short, conical spines.
_Dimensions._--Diameter of the sphere 4.5, of the meshes 0.1 to 0.2;
breadth of the bars 0.006.
_Habitat._--Central Pacific, Station 271, depth 2425 fathoms.
{1637}Genus 690. _Aulodictyum_,[309] Haeckel, 1879, Sitzungsb. med.-nat.
Gesellsch. Jena, Dec. 12, p. 6.
_Definition._--#Aulosphærida# with polygonal meshes in the network, the
tubes of which are connected in different directions and form the spongy
wall of a spherical shell. No radial tubes prominent over the surface.
The genus _Aulodictyum_ differs from _Aulonia_, its ancestral form, in the
development of a spongy framework in the thickened wall of the spherical
lattice-shell. It bears therefore to the latter the same relation as
_Auloplegma_ does to _Aularia_. But the outer surface of the hollow sphere
is in _Aulodictyum_ completely smooth, as well as the inner, and bears no
radial tubes. Only one species of this genus has been observed.
1. _Aulodictyum hydrodictyum_, n. sp.
Shell spherical, smooth on the outer and inner surfaces, composed of an
irregular framework of straight and smooth cylindrical tubes; its meshes
very irregular, of unequal size and various forms. The diameter of the
sphere is about six or eight times as great as the thickness of its
reticular wall.
_Dimensions._--Diameter of the sphere 2 to 3, of its meshes 0.1 to 0.2;
breadth of the bars 0.01.
_Habitat._--Antarctic Ocean, Station 157, depth 1950 fathoms.
Family LXXVII. #CANNOSPHÆRIDA#, Haeckel (Pl. 112).
_Cannosphærida_, Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena,
Dec. 12, p. 6.
_Definition._--PHÆODARIA with two concentric spherical or subspherical
shells, which are connected by numerous thin, tubular, radial beams. Inner
shell simple, spherical or ovate, solid or latticed, with a peculiar mouth.
Outer shell spherical or polyhedral, articulate, composed of hollow
tangential tubes, which are separated by astral septa at the stellate nodal
points. From the latter arise hollow radial tubes, whilst the inner radial
beams, connecting the two shells, are inserted in the middle of the
tangential tubes. No peculiar mouth in the outer shell. Central capsule
enclosed by the inner shell.
The family #Cannosphærida# comprises a small number of remarkable PHÆODARIA
which are rare and found only in a few localities. They differ from all the
other PHÆODARIA in the possession of two concentric spherical shells, which
are connected by radial beams, and the inner of which is quite simple, like
that of the Medusettida, {1638}whilst the outer is articulated and composed
of hollow tangential tubes, like that of the Aulosphærida. This latter
family seems to be most nearly allied to the Cannosphærida, and is perhaps
derived from them by loss of the inner shell. The possession of a peculiar
mouth in this inner shell brings the Cannosphærida nearer to the
Phæogromia. The similar Coelodrymida, in which also two concentric
spherical shells are connected by hollow radial beams, differ essentially
in the bivalved shape of the inner shell and the simple, non-articulated,
network of the outer shell.
Only a single species of Cannosphærida has been hitherto known, described
and figured in 1879 by R. Hertwig as _Coelacantha anchorata_ (_loc. cit._,
p. 92, Taf. ix. fig. 2). The rich collection of the Challenger has added to
it only four other species, one of which is most nearly allied to the
former, whilst the others belong to a separate genus, _Cannosphæra_ (Pl.
112). The inner shell is in this latter genus a solid lamella of silica,
whilst in the former it is fenestrated. In all other essential points of
structure both genera are scarcely different.
The inner shell is either spherical or ovate and has a diameter of 0.1 to
0.4 (usually 0.2 to 0.3 mm.). A distinct main axis is always marked by the
large open mouth on its oral pole. The aboral part of the shell-cavity
contains the spherical central capsule, the oral part the dark phæodium, a
part of which is often prominent through the mouth (figs. 1, 2, 4). The
wall of the inner shell is a very thin and transparent lamella of silica,
which is structureless and solid in _Cannosphæra_, distinctly fenestrated
in _Coelacantha_; the pores of the latter are irregularly rounded and seem
to possess a thickened margin.
From the surface of the inner shell arise numerous thin tubular, radial
beams (twenty to eighty or more) and connect it with the outer shell. These
beams are always very thin and straight cylindrical tubules, about twice to
four times as long as the diameter of the inner shell, and usually 0.001
mm. broad, or even less. Their basal end at the surface of the latter
appears mammillated (figs. 2, 4). The cavity of the inner shell seems to
pass over immediately into the tubular cavities of the radial beams. These
latter are sometimes simple, at other times articulated or jointed by a
number of transverse septa. The radial beams are covered in all the species
observed either with scattered spines (fig. 5) or with verticils of
anchor-threads, very thin, filiform, lateral branches which bear a
spathilla with three or four recurved teeth on the distal end (figs. 2, 4).