dcsimg

Description

provided by NMNH Antarctic Invertebrates

"Cellarinella foveolata sp. nov.

(Pl. V, figs. 2a-h)

Zoarium cylindrical, branching in various planes, with spreading calcareous base. Some colonies are as much as 50mm in height. The surface is deeply pitted without zooecial divisions, the peristomial aperture is broad and short (often having the shape of a new moon), with a raised cap over the distal end, and sometimes, but not often, it is also raised below the aperture; there is a plate within the proximal edge of the peristome directed downwards. In the older zooecia the secondary aperture is round, and below the aperture, in some zooecia, there is a round avicularium with a semicircular mandible, while in older zooecia the avicularium may be within the peristome.

The oral aperture is a considerable distance from the peristomial opening and at right angles to it, the shape being nearly round with the proximal edge straightened. No operculum can be prepared out, nor is any seen in cut sections, only a membranous contraction. The ovicell is but little raised, and is not always visible on the surface. There are about four lateral rosette plates, each with about ten communication pores, and there is one distal plate, over which there is a pair of spinous processes, which are sometimes very slender, in other cases stouter (fig. 2g). There are about 22 tentacles.

This is very much like a CHALLENGER specimen from Station 320, mentioned and figured in my Supplementary Report (2), however the Challenger one is slighter and the pores are more elongate, and I describe the mandibles as triangular, but a mandible seen sideways or within the peristome often appears more triangular than is the case.

This and Systenopora contracta nov. differ from Myriozoum as represented by M. truncatum Pall. in not having thick opercula, and further in the shape of the aperture ; also in having lateral rosette plates with several communication pores. As I have elsewhere shown M. truncatum, and Porina gracilis Ed. have wide tubes from the surface, and also from zooecium to zooecium, but no distinct rosette plates. Haswellia has many similar characters, but has a suboral pore, and a thick Schizoporellidan operculum. There seems to be most resemblance to Tubucellaria, which however is jointed, though this is a character on which we should not place much importance. The generic name is chosen on account of this resemblance.

In 609 and 611 there are no polypides, but degenerate remains and many buds, also ovaria in the zooecia consisting of two or three rather large cells, situated by the lateral wall, about half way between the two extremities. The walls of the compensation sac are visible.

HABITAT. - Exp. Antarct. Belge.

Nos 560, 596, Tangles VII. Lat. 70º 23' S.- Long. 82º 47' W.; 480 met.; +0.8 C.

Nos 609, 611, 619, 621, 623, 683, 691, Tangles VIII. Lat. 70º 00' S.- Long. 80º 48' W. ; 500 ? met.; +0.9 C.

No 743, Tangles IX. Lat. 70º 20' S.- Long. 83º 23' W. ; 459 met.;+0.8 C.

This specimen is nodulated (see fig. 2e) and has a pronounced shelf on the distal end of the oral aperture.

Nos 799, 1028, Tangles X. Lat. 70º 15' S.- Long. 84° 06' W. ; 569 met.; +0.8 C.

(2) Zool. Chall. Exp., vol. XXXI, pt. LXXIX, p. 3g, pl. III, fig. 47."

(Waters, 1904: 57-8)