Owen, 1834
Description:
Small animals with a short, posteriorly rounded mantle. Anterior edge of the mantle is not fused with the head on the back. Head is wide. Dorsal side of head and mantle are beset by small rounded papillae whose number, size, and distribution vary greatly. In typical case the papillae are large and sparsely dispersed, but in juveniles and some local forms they are small and poorly visible. Fins are kidney-shaped. Tentacles are retractile with well defined clubs. Tentacular club is widened, not bent. Club suckers are arranged in 7-10 rows, approximately of similar size, there are not greatly enlarged suckers. Arms are fairly short, but well developed. Arm suckers are arranged in two rows in the middle part of arms. Luminous organs are frequently present on the ink sac. A muscular septum present in the mantle cavity.
Habitat:
Benthic animals.
Distribution:
Arctic-boreal Atlantic species. From Greenland and Spitzbergen to the Kara Sea and Canadian Arctic Archipelago, southward to South Carolina and the western Atlantic and Scotland and the northern part of the North Sea in the eastern Atlantic (Distr. R. palpebrosa). Common in the Barents Sea and the Kara Sea; absent in the White Sea.