Cavolinia uncinata

Abstract

Cavolinia uncinata (d'Orbigny, 1835) (Figs 4 I-L, 4R-S) Description. – A medium large Cavolinia (L 7.5 mm) with rounded dorsal lip, ventral lip with median depression, and long caudal spine. Relatively straight sides. The dorsal shell has five longitudinal ribs, a marked central rib and narrower lateral and lock ribs, all weaker towards the caudal spine, otherwise smooth with flattened edge. Ventral part of the shell globose and smooth. The lateral spines are medium long and point outward in caudal direction. Shell white to brownish. Remarks. – Differs from Cavolinia globulosa in relatively straight parallel sides, having narrower and more marked longitudinal ribs, lack of transverse riblets, longer caudal spine and longer lateral spines that point outward. The larval shells / caudal spines (Figs 4 K-L, 4R-S) are wider than those of C. inflexa (Figs 4 MQ), and lack the lateral carinae, but have narrow flattened sides with short lateral ridges. Distribution. – Four specimens found on the Brunei middle to outer shelf (MES15, 24, 25); 16 on the outer shelf off Sarawak (DD29, DD36), some specimens, fragments and larval shells / caudal spines on the continental slope off Sarawak (DD15) and the outer shelf of Sabah (DD92, DD93); and a larval shell / caudal spine at Royal Charlotte atoll.

Authors 4

1. Han
2. J. G. M.
3. Raven Aachen

   Naturalis Biodiversity Center

   Affiliation as printed

   Research Associate, Naturalis Biodiversity Center, Leiden, The Netherlands. E-mail: han. raven @ naturalis. nl; https: // orcid. org / 0000 - 0002 - 5305 - 0795

4. David J. Marshall

   Universiti Brunei Darussalam

   Affiliation as printed

   Environmental and Life Sciences, Faculty of Science, Universiti Brunei Darussalam, Brunei Darussalam. https: // orcid. org / 0000 - 0003 - 3771 - 5950 * Corresponding author. E-mail: david. marshall @ ubd. edu. bn