Leptaxinus, Verrill & Bush, 1898

Leptaxinus View in CoL “ scandica ” Ockelmann MS

Figs 7–9

In the archive, this species is represented by stipple drawings of the shell, hinge and prodissoconch ( Fig. 7) and a prospective holotype (NHMD-1175765) is present from Ingolf stn 117, 69°13′ N, 08°03′ W,

at a depth of 1843 m, S of Jan Mayen in the Norwegian Sea ( Fig. 8 View Fig ). Related samples are: 1 dry shell, labelled “ T. ( Leptaxinus) incrassatus (Jeffr.) Ingolf stn 36, Tegnet K. Olsen; 61°50′ N, 56°21′ W, 2702 m, 1895” (NHMD-1175773); 3 valves + 1 broken, labelled “ Leptaxinus n. sp. incrassatus aff. [Ingolf] stn 119” (NHMD-1175749); 12 valves, labelled “ Leptaxinus incrassatus (Jeffreys) Ingolf stn 18, det. Ockelmann” (NHMD-1175752).

In a pencil sketch ( Fig. 7D), Ockelmann compared L. “ scandica ” with L. incrassatus ( Jeffreys, 1876) and L. minutus Verrill & Bush, 1898 , the major difference being the very large size of the prodissoconch of L. “ scandica ” at 207 µm. Ockelmann’s map ( Fig. 9 View Fig ) indicates he had it from three stations in the deep Norwegian Sea, but I have seen only the one shell designated as the holotype. Comparisons with species illustrated by Payne & Allen (1991) reveal no identical species and the hinge details do not match that of L. minutus as illustrated by Verrill & Bush (1898). It is also possible that Ockelmann’s N Atlantic “ scandica ” is the same as the more recently described Mendicula ockelmanni ( Keuning & Schander, 2010) , as both come from abyssal depths in the Norwegian Sea. Another similar form is the “ Thyasira n. sp. ” illustrated by Bouchet &Warén (1979) and collected from the deep Norwegian Sea. They stated that many specimens were given to Ockelmann, who intended to describe this species but never did, nor are there any notes in the archive. The specimens are in the Ockelmann collection, but my observations suggest it is not the same species as “ scandica ”, due primarily to the size and sculpture of the prodissoconch.