(Campbell and Clark, 1944)
Description - Add description
|Lithomelissa campanulaeformis |
Shell large, bell-shaped (its length 1.4 basal diameter); cephalis with three horns, one large, stout, conical, probably bladed, primary occipital, a smaller one secondary frontal at an angle to first, and a third yet smaller, needlelike one, parietal horn; cephalis tall, distally rounded and with a subcylindrical body, higher than wide, its sides with small, spinelike thorns; thorax subdivided by lateral changes in contour into two sections, upper section subequal to lower and less wide (about 0.4 total length in length), with very broadly rounded, wide shoulder below cervix and subcorneal (43°) sides, with three flat, triangular, equidistant, blades or wings below shoulder and with numerous, short, sharp thorns arising as sepaloid points from angles of pore- frames; lower thoracic section strongly bicovex, with greatest diometer near middle (1.1 apertural diameters), thence reduced to shell aperture which has about same diameter as basal mouth of upper thoracic section, its surface smooth; shell-aperture simple; wall thickened in upper thorax; pores of cephalis tiny, circular, well separated, shallow, and with gray shell material between them, pores of thorax much larger, circular, elliptical to subhexagonal, some larger than others, deep-set, especially in upper thorax, about 20 around widest part of lower thorax, not in rows (arranged like bee comb). Length, total, 230ì, of thorax, 180ì; diameter, widest, 180 ì, of aperture, 170ì , of largest pores, 22ì.
Lithomelissa campanulaeformis n.sp. differs from corythium (Ehrenberg, 1875) in possessing a less wide, less flat shell, and in lateral wings.
|Campbell and Clark 1944|
| Sethoconus (?) dogieli |
Skeleton consisting of two segments. First segment, "cephalis," considerably smaller than second. "Cephalis" with numerous small pores, often these are filled with skeletal substance leaving on surface only small depressions — honeycomb. First segment distinctly demarcated from second. Upper part of second chamber conical, with smaller pores than in cylindrical lower part. Pores gradually enlarging towards bottom of shell; they are irregularly polygonal. Many supplementary needles and
spines on surface of shell. Internal skeleton composed of basic elements (needles MB, A, Vert, D, Lr and Ll), al l of them comparatively slender and weakly marked. Externally needles A and Vert forming two horns on "cephalis," needles D, Ll and Lr directed obliquely downwards, pass through the wall of the second segment, but not forming stout processes of the shell and not always well marked, particularly when concealed among the numerous supplementary needles.
Dimensions: length of first segment about 35μ, width about 40μ, length of second segment 150μ and more, width 100 —120μ.
Location. Found in many samples of deepwater sediments of the Antarctic in Indian and Pacific Ocean sectors. Shells of this species
usually constitute less than 1% of total number.
Holotype in ZIN collection preparation No. 1 of station 29 of the "Ob' "
Note. This species is similar to the foregoing S. (?) reschetnjakae, but differs from it by the structure of the wall of the "cephalis" and by the more slender skeletal wall of the second segment. The structure of the shell is quite similar to that of Pterocorys (?) hirundo Hck. and P. irregularis Cleve, but these two species differ from ours by the far stouter external extensions of needles D, Ll and L r . Therefore we describe it as a new species. Its relationship to genus Sethoconus Hck., like that of the two above species, is conditional and based only on its formal fitting in with the diagnosis of this genus by Haeckel. There is a definite similarity to representatives of genus Cycladophora Ehr. (see below), but it is inadequate for relating S. (?) dogieli to this genus.
The species is named in memory of Valentin Aleksandrovich Dogel', who devoted the last years of his life to the study of radiolarians.
|Lipmanella (?) dogieli |
The number of pores is less than in Lipmanella sp.C-only about 7 pores on a half equator. Pores are irregular and of different sizes. There is no subdivision into thorax and abdomen.
Remark: This species is very similar also to the Miocene species described as Lithomelissa campanulaeformis by Campbell and Clark (1945, p. 44, pi. 6, fig. 1), see Plate 37, Figure 11 in the present report. Lipmanella (?) dogieli differs from L. campanulaeformis by smaller dimensions. Perhaps it represents by itself only Quaternary subgenus of the Miocene species L.campanulaeformis.
|Petrushevskaya and Kozlova 1972|
Differs from the species mentioned above by the companulate shell outline, having no subdivision into thorax and abdomen. It differs from these species also by its polygonal, large pores arranged near each other. The species appears in the Antarctic in early Miocene in the atypical form (Plate 25, Figure 5), and it is known to exist up to Recent.
Remarks: First segment somewhat rough, without spines externally, without strictures along AL and I'. Apical horn shorter than height of first segment. Ventral horn much shorter than apical horn. Pores in first segment very small, circular and distributed in only its lower part. Second segment expanding little distally and with many spines externally. Pores in second segment circular to subcircular, larger than those in first segment and with longitudinal hexagonal pore frames. Distal aperture of second segment wide opened, without distinct rim or teeth. Appendages on internal spicule composed of ar, al, pd, pv, jr, jl, cr and c|. Connecting arches composed of AL (arpv and alpd), LV (pvjr and pvjl) and DL (crpd and clpd). Right and left I' distinct and extending toward the dorsal side on the shell wall. Internal spicule circular in cross section except for the distal parts of A and V (apical and ventral horns) that are three-bladed. V bending a little anticlockwise. Ax on left L near at the junction with MB somewhat indistinct.
Dimensions (in μm) (measurements based on 6 specimens): Maximum breadth of first segment: 32-45 (average - 39); Maximum breadth of second segment: 128-152(139); Height of first segment (without apical horn): 32-48 (39); Total height of shell (without apical horn): 140-180 (164).
Occurrences: Oik-7; Upper Miocene.