Cryptopecten, Dall, Bartsch & Rehder, 1938

Dijkstra, Henk H. & Maestrati, Philippe, 2010, Pectinoidea (Mollusca, Bivalvia, Propeamussiidae, Entoliidae and Pectinidae) from the Austral Islands (French Polynesia), Zoosystema 32 (2), pp. 333-358 : 351

Cryptopecten sp. A

( Fig. 5A )

MATERIAL EXAMINED. — Récif Neilson. BENTHAUS, stn DW 1925, 27°00’S, 146°05’W, 560-790 m, 1 rv.

DISTRIBUTION. — Austral Islands, only a single valve at 560 m depth.

REMARKS

The present specimen somewhat resembles Cryptopecten phrygium ( Dall, 1886) , from the tropical western Atlantic, in having an identical sculpture of longitudinal hollow sections on both sides of the primary radial ribs and intercostal commarginal lamellae. A similar sculpture also exists in Cryptopecten vesiculosus (Dunker, 1877) , from southern Japan, and in C. bullatus and C. nux ( Hayami 1984) . A delicate shell layer covers these hollow sections ( Hayami 1984: pl. 13, fig. 1c), but in eroded specimens this shell layer is often lacking and a longitudinal groove appears on each side of the main ribs. The present specimen is considerably larger in size than the other Cryptopecten species ( Cryptopecten sp. A 57 mm, C. phrygium 43 mm, C. vesiculosus 34 mm, C. bullatus 25 mm, and C. nux 20 mm in height) ( Hayami 1984), and strongly posteriorly oblique (other Cryptopecten species are more circular). Because a single valve is available, this new species is not named here.

Figures

FIG. 5. — A, Cryptopecten sp. A, external view of the right valve; B, Anguipecten lamberti (Souverbie, 1874), external view of the left valve; C, Anguipecten picturatus Dijkstra, 1995, external view of the left valve; D, Anguipecten superbus (Sowerby II, 1842), external view of the right valve; E, Glorichlamys elegantissima (Deshayes, 1863), external view of the right valve; F, Gloripallium spiniferum, (Sowerby I, 1835), external view of the right valve; G, H, Mirapecten mirificus (Reeve, 1853), external views of the left and right valves.