Hyalopecten tydemani

(Dijkstra, 1990)



Holotype (lv)

Original name   Palliolum (Hyalopecten) tydemani Dijkstra, 1990
Autoreference   Dijkstra, 1990: 7, pl. 2, fig. 13.
Reference   Dijkstra, H.H. ,1990. Three new pectinacean species from the Indonesian Archipelago collected during the Siboga expedition (1899-1900) with additional information and corrections on the previous report (Mollusca: Propeamussiidae, Pectinidae). - Beaufortia 40: 1-14, 17 figs.
Type data   Holotype (lv: H 9.1 mm, L 7.5 mm) Zoological Museum, University of Amsterdam, Amsterdam (ZMA Moll. 3.89.009). Type locality: Indonesia, Ceram Sea, 02*40'S, 128*37.5'E, 835 m, dead, blue muddy bottom, 02.09.1899 ("Siboga" stn 178).

  Shell up to ca. 10 mm high, thin, semi-transparent, right valve more convex than left valve, higher than wide, inequivalve, inequilateral, auricles nearly equal in size, unequal in shape, umbonal angle ca. 85 degrees, colour dirty white.

  Left valve and right valve sculptured with very closely spaced commarginal lamellae. Auricles only with commarginal lamellae. Posterior auricle continuous with disc and with prominent commarginal lamellae. Anterior auricle of right valve demarcated from disc.

Byssal notch deep, byssal fasciole rather narrow, ctenolium obsolete.



Indonesia, Ceram Sea (TL)

Habitat   Probably living bathyally on soft bottom assemblages.