Septicollarina sp.

Bitner, Maria Aleksandra, 2008, New data on the recent brachiopods from the Fiji and Wallis and Futuna islands, South-West Pacific, Zoosystema 30 (2), pp. 419-461 : 437-438

Septicollarina sp.

( Fig. 16A )

MATERIAL EXAMINED. — Fiji. BORDAU 1, Lau Rigde, stn CP 1409, 1 complete specimen.

DEPTH RANGE. — 557- 558 m.

MEASUREMENTS. — Length 11.1 mm, width 12.2 mm, thickness 7.7 mm.

DESCRIPTION

Shell of medium size, thin, transversely pentagonal, strongly ventribiconvex. Shell surface smooth with scarcely visible radial capillae. Anterior commissure strongly unisulcate. Beak short, incurved with well-defined beak ridges. Foramen large, circular, permesothyrid; deltidial plates minute.Ventral valve interior with strong, well-developed dental plates and wide pedicle collar supported by a short median septum. Dorsal valve interior with a long medium septum, high posteriorly and low anteriorly, and inner hinge plates attached to the septum, forming septalium. No cardinal process observed. Crura very thin and relatively long. Loop partly broken but narrow descending branches, which bend to become broad ascending branches, are visible; transverse band not preserved.

REMARKS

The investigated specimen displays all the characters of the genus Septicollarina ( Zezina 1981, 1990). Until now two species of this genus have been described: S. hemiechinata Zezina, 1981 from off Java, and S. oceanica Zezina, 1990 from the Eastern Pacific. The specimen from Fiji is nearly twice as large as these species, although the specimen from off Java may be young because its gonads were not developed ( Zezina 1981). The Fiji material differs in being strongly unisulcate and having an incurved beak. From S. hemiechinata the specimen differs also in having a longer ventral septum which in S. hemiechinata is equal to the length of the pedicle collar. The very limited material and not fully preserved brachidium allow determination only to the generic level.

Figures

FIG. 16. — A, Septicollarina sp., Fiji, Lau Ridge, BORDAU 1, stn CP 1409, 557-558 m, dorsal view of complete specimen (MNHN BRA-3088); B-G, Dallina triangularis Yabe & Hatai, 1934, Fiji, Lau Ridge, BORDAU 1, stn CP 1409, 557-558 m, dorsal, lateral and anterior views of complete specimens (MNHN BRA-3109, 3110). Scale bar: A: 0.5 cm; B-G: 1 cm.