|
Antarctissa spp. group? (Figure
3D, 15.104) [=?Antarctissa strelkovi, ?Antarctissa
longa]. Shell outline triangular to oval, cephalis
partly submerged into thorax. Shell-wall thick. A.
strelkovi (Figure 3D) and A. longa differ from
A. denticulata by having thinner and spinier
shell-walls. Shell height: 100-160 µm. Ref: Petrushevskaya (1967). |
|
Arachnocorys circumtexta
Haeckel (Figure 15.110). Spherical cephalis provided with
numerous spines; those directed upwards are
interconnected by a spider web-like lattice of very thin
bars; the ones directed toward the base support an
incipient thorax formed by a coarser lattice with
irregular pores, with several very large pores located in
the neck area. Overall shell height: ca. 140 µm. Ref: Petrushevskaya
(1971a). |
|
Callimitra carolotae Haeckel (Figure 15.123). The small, dome-shaped cephalis
is provided with very long apical (directed upwards),
dorsal and main lateral spines (directed down and
sideways) interconnected by a delicate meshwork which
forms three basal plates and three lateral plates.
Overall shell height: ca. 200 µm. Ref: Haeckel (1887). |
|
Clathrocanium coarctatum
Ehrenberg (Figure 15.114). Cephalis with a large,
three-bladed apical horn which may have lateral
thread-like, anastomosing pojections. The dorsal and two
main lateral spines, directed down and sideways, are
joined by narrow lattice plates which form a small
thorax. Overall shell height: ca. 100 µm. Ref: Petrushevskaya
(1971a). |
|
Clathrocorys teuscheri
Haeckel (Figure 2G;
15.112). Similar to C. coaerctatum,
except that the apical, dorsal and main lateral spines
are joined by a well-developed lattice. Overall shell
height: ca. 150-190 µm. Ref: Petrushevskaya
(1971a). |
|
Helotholus histricosa Jorgensen (Figure 15.113). Spiny, dome-shaped shell.
Cephalis merging smoothly with thorax; thorax with large
and irregular pores, without defined termination. Maximum
shell width: ca. 100-120 µm. Ref: Petrushevskaya
(1971a). |
|
Lampromitra coronata Haeckel (Figure 15.115). Shell in the shape of a Chinese
peasant hat. Thorax with subregular circular pores
increasing in size slightly towards the base, with a well
defined peristome of a row of small pores and minute
spines. Shell diameter: ca. 200 µm. Ref: Petrushevskaya
(1971a). |
|
Lampromitra danaes (Haeckel) (Figure 15.116) [=Corocalyptra danaes].
Overall shell-shape similar to L. coronata. Pores
on thorax regular, polygonal, strongly increasing in size
toward its base. Rim of thorax represented by a very
regular row of small, rectangular pores followed
inmmediately by one of much larger pores. Shell diameter:
ca. 180 µm. Ref: Haeckel (1887), as Clathrocyclas danaes. |
|
Lampromitra quadricuspis
Haeckel (Figure 15.117). Generally similar to L.
coronata, except that cephalis is more elongate,
pores on thorax are larger and its termination is ragged.
Shell diameter: 120-350 µm. Ref: Benson (1966). |
|
Lampromitra schultzei (Haeckel) (Figure 15.118). Similar to L. coronata,
except that pores on thorax are considerably larger and
less regular. Peristome with two-three rows of regularly
aligned, small, subrectangular pores. Shell diameter: ca.
100 µm. Ref: Boltovskoy and
Riedel (1980). |
|
Lophophaena butschlii (Haeckel) (Figure 15.108). Elongated cephalis, the top of
which is usually unfinished, short conical thorax.
Overall shell height: ca. 100 µm. Ref: Petrushevskaya
(1971a). |
|
Lophophaena hispida (Ehrenberg) (Figure 3I; 15.109). Cephalis spherical, with very
large pores and many long, thin spines. Thorax conical,
its pores decreasing in size toward the base; sometimes
an incipient abdomen present. Overall shell height: ca.
150 µm. Ref: Petrushevskaya
(1971a). |
|
Neosemantis distephanus
(Haeckel) (Figure 15.120). Skeleton composed of an oval or
pyriform ring (fused main lateral spines) both poles of
which are connected by a third bar (the apical spine);
from its base protrudes the dorsal spine. All skeletal
elements very spiny. Major ring diameter: 70-80 µm. Ref:
Petrushevskaya
(1971a). |
|
Peromelissa phalacra (Haeckel) (Figure 15.107) [=Psilomelissa phalacra, Lithomelissa
monoceras]. Oval cephalis whose upper part is
unperforated or has very few, very small pores. The
dorsal and main lateral spines emerge in the neck region
as large, three-bladed appendages. Overall shell height:
ca. 100 µm. Ref: Petrushevskaya
(1971a). |
|
Phormacantha hystrix (Jorgensen) (Figure 15.111). Cephalis composed of a loose
network of arches defining large, irregular pores. Thorax
absent. Shell height: 60-70 µm. Ref: Petrushevskaya
(1971a). |
|
Plagoniidae group (Figure 15.105). Includes many generally similar
forms with a latticed cephalis and with or without a
rudimentary thorax. The systematics of these sometimes
extremely abundant forms is confused, and they are
generally ignored in most surveys. They include species
cited under a variety of generic names, such as Amphiplecta,
Arachnocorallium, Arachnocorys,
Ceratocyrtis, Dimelissa, Lophophaena,
Lophophaenoma, Micromelissa, Peromelissa,
Psilomelissa, etc. |
|
Pseudocubus obeliscus Haeckel (Figure 15.122). Skeleton represented by the
sharply three-bladed edges of a 4-sided, truncated
pyramid. Shell height: ca. 40 µm. Ref: Petrushevskaya
(1971a). |
|
Sethophormis aurelia Haeckel (Figure 3F; 15.121). Shell in the form of a Chinese
peasant hat; cephalis cupola-shaped; thorax with a very
delicate, lace-like meshwork of irregular pores
decreasing in size toward the periphery and many radial
sinuous ribs. Shell diameter: 150-200 µm. Ref: Petrushevskaya
(1971a). |
|
Sethophormis rotula (Haeckel) (Figure 15.124). Central part of spider web-like
skeleton is an hexagonal ring whose vertices support 6
radiating spines; three additional radial spines (dorsal
and two main lateral) merge in center of hexagon. All
spines produce rather regularly spaced anastomosing
lateral branches. Diameter of central hexagon: ca. 40
µm. Ref: Petrushevskaya
(1971a). |
|
Tetraplecta pinigera Haeckel (Figure 15.119). Skeleton reduced to four
equidistant three-bladed spines arising from a common
central point; spines produce thin lateral braches which
can anastomose forming a delicate, irregular web. Length
of each spine: 25-30 µm. Ref: Haeckel (1887). |
|
Trisulcus triacanthus Popofsky (Figure 15.106). Small, sparsely perforated
cephalis sitting on top of a conspicuously
three-lobulated thorax, lobes are most evident in the
uppermost part, disappearing gradually toward the base.
Shell height: ca. 60 µm. Ref: Petrushevskaya
(1971a). |