220 On the AiTangement of the Nudibranch Mollmks. 



Fam. 5. Proctonotid^. Tentacula simple, linear, not 

 sheathed ; gills fusiform, on the sides of the back ; vent dorsal ; 

 jaws horny, strong. Proctonotus, Antiopa. 



Fam. 6. Diphyllidiad.e. Tentacula simple, united, ex- 

 panded?; gills in folds on the under side of the edge of the man- 

 tle, which is bent up ; jaws horny. Diphyllidia. 



b. Tongue narrow; teeth in a single central series. 



Fam. 7. DoxoNiDiE. Tentacula sheathed at the base, retrac- 

 tile ; gills fusiform, on the sides of the back. Doto. 



Fam. 8. Glaucid^. Tentacula subulate, simple, rarely ringed, 

 contractile ; gills fusiform or branched, on the sides of the back.; 

 jaws often horny. «. Glaucus ; /B. Eolidia, Montagua, Favorinus ; 

 7. Embletonia; S. Hermtea; e. Alderia. 



Fam. 9. Placobranchid^. Tentacula subulate or linear, 

 folded ; gills in the form of plaits or vessels radiating on the sur- 

 face of the back. Placobranchus, Elysia. 



Fam. 10. LiMAPONTiADiE. Tentacula none or simple, con- 

 tractile ; body depressed ; gills none external. Limapuntia. 



Fam. 11. Phyllirrhoid^. Tentacula elongate- subulate; 

 body compressed vertically ; gills none external. Phyllirrhoe. 



c. Tongue and jaws none. 



Fam. 12. Phyllidiad^. Tentacula dorsal, anterior, retrac- 

 tile ; labial palpi close, conical, small ; gills in form of radiating 

 folds on the under side within the edges of the mantle; vent 

 medial, postei'ior. 



The examination of the specimens of this family has caused 

 me to divide them into two genera, and to add a species which 

 does not appear to have been before noticed. 



Phyllidia. Vent dorsal, in the middle of the hinder part of 

 the back. 



1. Phyllidia trilineata, Cuvier, Ann. Mus. v. t. 18. f. 1-6. 



2. Phyllidia ocellata, Cuvier, Ann. Mus. v. t. 18. f. 7. 



3. Phyllidia annulata. Black, with three series of large, un- 

 equal-sized white rings, and with a row of minute white warts 

 near the mai-gin ; aperture of tentacles with small white warts 

 on each side. Var. 1. Central series of four rings. Var. 2. Cen- 

 tral series of live rings, the last behind the vent. 



Hab. Lord Hood's Islands. Brit. Mus. Two specimens. 

 The Phyll. ocellata of Cuvier has only five white rings, one in 

 front and two on each side. 



