(See Eliot on Coryphella beaumonti in Notes on some British Nudibranchs, Journ. Mar. Biol. Assoc., vol. vii., No. 3, June, 1906, pp. 361–3; and Nils Odhner on Cumanotus laticeps in Northern and Arctic Invertebrates, iii. Opisthobranchia. Kngl. Svenska Vetenskapsakademiens Handlingar. Band 41, No. 4, 1907, pp. 29, 80, and 101–2).

In describing (l.c.) Coryphella beaumonti as a new species, I pointed out that in many important characters it differs markedly from the other known Coryphellœ, and might be made the type of a new genus. But I did not create a new genus, thinking it might be well to examine further specimens, both of this animal and of allied forms, before deciding on its place in the classification. In the next year Odhner created (I.c.) the genus Cumanotus to which Coryphella beavmonti is certainly referable, and which is shown by his researches to be well characterized. It is allied to Coryphella inasmuch as it has unperfoliate rhinophores, tentacular angles to the foot, a triseriate radula and denticulate jaws; but it also possesses the following special characters: (1) The oral tentacles are very small and connected by a cutaneous fold which runs across the head; (2) there are several (at least, as many as three) rows of cerata in front of the rhinophores; (3) the verge is deeply grooved, and there is a bursa copulatrix, the entrance to which bears on its upper and lower margin a circular pad, armed on the periphery with twelve small cones terminating in hooks.