BRITISH NUDIBRANCHIATE MOLLUSCA. 



XIX 



Gen. 11. Triopa, Johns, Body depressed; cloak small, covering the head, 

 with linear, or subclavate marginal appendages ; dorsal tenta- 

 cles laminated, with tight sheaths ; oral tentacles cylindrical ; 

 branchiae non-retractile. Tongue rather broad, with numerous 

 plates, the two innermost on each side bearing large spines ; no 

 central plate .... 



Gen. 12. Ettplocamus, Phil. Body rather depressed; cloak small, covering 

 the head, the margin surrounded with branched appendages ; 

 dorsal tentacles laminated; oral tentacles in form of oval 

 lobes ; branchiae non-retractile. Tongue broad, with numerous 

 elongated plates, the 3 innermost on each side bearing large, 

 broad spines ; no central plate. A spinous buccal collar 



Gen. 13. Plocamopherus, Rupp. (Peplidia,Lo^e.) Body limaciform ; cloak 

 obsolete, forming an expanded veil over the head, with branched 

 appendages, and 2 or 3 tubercles on each side of the back ; 

 dorsal tentacles laminated; oral tentacles flat; branchiae 

 branched, non -retractile ; a fin-like carinated ridge down the 

 posterior part of the back to the tail. Tongue ? Jaws ? 



Gen. 14. iEoiRus, Loven. Body convex, covered with large tubercles • 

 cloak indistinct, forming a veil over the head and a tubercu- 

 lated ridge on each side ; dorsal tentacles 2, linear, smooth, 

 with wide sheaths ; branchial plumes non-retractile. Tongue 

 broad, with numerous simple, curved, lateral spines ; no central 

 plate. An upper corneous jaw 



Gen. 15. Ceratosoma, Gray. Body elevated; cloak wanting; dorsal 

 tentacles laminated, retractile ; branchiae retractile within a 

 cavity ; back produced posteriorly into a conical protuberance 

 behind the branchiae. Tongue broad, with numerous rows of 

 simple spines ; no central spine. A spinous buccal collar 



TYPE. 



T. claviger, Mull. 



E. croceus, Phil. 



P. ocellatus, Rupp. 



M. punctilucens, D'Orb. 



C. trilobata, Gray. 



Sub-Order — Polybranchiata. 



Tribe 1. Liver generally central; branchiae laminated. 



Section 1. With the branchiae on the under side of the cloak. 



Fam. 3. Phyllidiadce. 



Gen. 16. Phyllidia, Cuv. Cloak covering the whole body, tuberculated 

 or pustulated; dorsal tentacles laminated ; oral tentacles small, 

 linear; branchiae surrounding the body, interrupted only by 

 the head; anus median, in the posterior part of the cloak. 

 No tongue. No jaws 



Gen. 17. Eryeria, Gray. Like the last, but with the anus situated be- 

 neath the cloak posteriorly 



P. trilineata, Cuv. 



F. pustulosa, Cuv. 



