Subfamily Velutininae

Velutininae are distributed in all Arctic and temperate areas. They have the same radular formula as Marseniopsinae and Hainotinae (2:1:1:1:2), but with a larger base on the lateral and central teeth. In this group, the jaws have a characteristic appearance, being composed of scale-like elements (as in Marseniopsinae) presenting a denticulation on the masticatory side (Fig. 11A, M). Velutininae were thought to include all velutinid species with a shell completely or partly exposed (some with a small fissure in the centre of the dorsum). However, we found at least nine additional species, belonging to two new genera in subfamily Lamellariinae and one in Marseniopsinae, that possess a small fissure on the dorsal mantle, showing that this morphological character is not diagnostic at the subfamily level.