I DA LI A. 01 



S////. Tritonia, Lam., not Car. Psiloccros, Menke. 

 Cladophora, Gray. 



Ex. T. clavigera, Midler, pi. 64, fig. 2. 



The sheaths of the tentacles in Triojpa are simple ; the 

 forehead is famished with radiating papillose appendages ; 

 and the margin of the mantle is adorned with blunt, curved, 

 cylindrical processes, arranged round the margin. The 

 species are inhabitants of European seas. 



Species of Triopa. 

 clavigera, Mutt. lacera, Midi. 



Genus idalia, Leuckart. 



Teeth, central 1, lateral 22. Tentacles dorsal, linear, 

 laminated, with long, simple., sustentacular appendages, an- 

 terior to, and distinct from, them ; forehead simple, rounded. 

 Gills plumose, surrounding the vent. 



Syn. Okenia, Leuck. (olim), not Zctter. Euplocamus, 

 Phil. Peplidia, Lowe. 



Ex. I. aspersa, Alder and Hancock, pi. 64, fig. 3. 



This lovely Nudibranch is peculiarly distinguished by 

 the four elongated, tentacle-shaped appendages anterior to 

 the true tentacles; extending from these, and around the 

 branchial region, are other pointed processes. 



Species of Id alia. 



aspersa, Alder and Hanc. ina?qualis, Forbes. 



cirrhigera, Phil. laminosa, Phil. 



crocea, Phil. Leachii, Alder and Hanc. 



dubia, Sars. Madera), Loire. 



elegans, Leuck. pulchella, Alder and Hanc. 



frondosa, Phil. quadricornis, Mont. 

 vol. ii. K 



