, and some new Species of Naked Mollusca. ^63 



Family Polyceridae. 

 Crimora_, nov. gen. 



Body limaciform. Cloak nearly obsolete, forming a veil with 

 branched appendages over the head, and a papillated ridge on 

 the sides of the back. Dorsal tentacles laminated, retractile 

 within sheaths : oral tentacles tubercular. Branchice plumose, 

 non-retractile, placed about two-thirds down the centre of the 

 back. Tail short, without a fin-like crest. 



Tongue. — Lateral spines twenty-six or twenty-seven on each 

 side, of three kinds : the first next the centre large, hooked, bi- 

 cuspid ; the next five or six short, obtuse, and supported on 

 subquadrilateral plates ; the remainder very long, slender, curved 

 and minutely denticulated on the inner margin. No central 

 spine. 



This genus comes very near to Plocamophorus of Riippell, 

 agreeing with it in having a branched veil in front, but differing 

 in the absence of the large fin-like tail, and somewhat in the 

 character of the lateral appendages, which in Plocamophorus are 

 fewer, larger, and a little branched or papillated. It has also 

 considerable relationship with Thecacera, in which genus, how- 

 ever, the veil is either absent or very imperfectly developed, and 

 there are no oral tentacles. The members of this family, though 

 bearing great general resemblance, are so variable in details 

 that it is difficult to avoid raising each species to the rank of a 

 genus. We have been rather reluctant, in the present instance, 

 to add another to the number ; but the species above described 

 will not come into any of the known genera as at present under* 

 stood ; and the peculiar character of the tongue strengthens its 

 title to generic rank. This organ differs from that of any of the 

 allied genera in having very numerous, slender, denticulated, 

 lateral spines, as in the Trochidce. 



Crimorapapillatajn,^^, 



^ Body ovate- oblong, swelling a little in the centre and tapering 

 to a blunt point posteriorly; white, with the processes tipped 

 with yellow. Dorsal tentacles subclavate, pale yellow, retractile 

 within short sheaths : oral tentacles short, tubercular. Veil bi- 

 lobed, each lobe furnished with five more or less branched ap- 

 pendages, leaving a small vacant space in the centre. A slight 

 pallial ridge runs along each side of the back, bearing numerous 

 small filamentous papilla3 tipped with yellow, terminating behind 

 in a bifid process of no great size : an indistinct ridge runs 

 down the centre of the tail, also bearing yellow-tipped papillae, 

 the anterior one of which is larger than the rest, and bifid; 

 similar small papillse are disposed over the body, forming a line 



