Caecum cf. succineum de Folin, 1880

Walter, Angelo Vannozzi & Renda, Walter, 2024, Sampling the depth: New data on the Caecidae (Mollusca, Gastropoda) from northeastern Papua New Guinea, Zoosystema 46 (14), pp. 327-347 : 338

Caecum cf. succineum de Folin, 1880

( Fig. 6F )

MATERIAL EXAMINED. — Papua New Guine a • 1 sh; New Ireland; KAVIENG 2014 Stn DW4495; 2°24’S, 149°55’E; 272-274 m depth; 6.IX.2014; MNHN .

DESCRIPTION

Shell small for the genus, smooth. Protoconch unknown. Teleoconch tubular, arched, almost smooth. Early teleoconch unknown. Adult shell tubular, slender, subcylindrical, slightly dextrally twisted, smooth. No sculpture except for very fine rings in the abapical part. Aperture preceded by a rounded, varix-like swelling crossed by growth lines. Septum low dome shaped without mucro lying slightly below the cutting plane. Length 1.5 mm.

REMARKS

A single, worn specimen comparable to C. succineum was found. Attribution to de Folin’s species is tentative due to the slenderer tube and the varix-like swelling before the aperture shown by this specimen. Caecum succineum is a widespread species occurring in the whole IWP ( Vannozzi 2023), but this species needs a revision in order to determine its range of variability.

Figures

FIG. 6. — Caecum Fleming, 1813 species from deep-water stations from northeastern PNG: A-D, C. dakuwaqa Pizzini, Raines & Vannozzi, 2013 from Stn DW4470 (C, D: juvenile); E, C. dakuwaqa from Stn DW4463; F, C. cf. succineum from Stn DW4495; G, C. neocaledonicum de Folin, 1868 from Stn DW4470; H, C. neocaledonicum from Stn DW4464; I, C. frugi Vannozzi, 2019 from Stn DW4412; J, C. frugi juv. from Stn CP4418; K, C. neoguineanum Vannozzi, 2019 from Stn DW4495; L, C. sp. from Stn DW4465 MNHN-IM-2022-2399. Scale bars: A-H, K, L, 1 mm; I, J, 0.5 mm.