BRITISH NUDIBRANCHIATE MOLLUSCA. 



xxi 



Fam. 8. Tetlddas. 



Gen. 25. Tethys, Linn. Body depressed, with numerous branchial 

 plumes or tufts alternating with papillae on each side of the 

 back; veil fringed with filaments; tentacles laminated, 

 sheathed. No tongue. No jaws 



Fam. 9. Melibina. 



Gen. 26. Melibe, Rang. Tentacles small, retractile within long, narrow, 

 trumpet-shaped sheaths; veil large, funnel-shaped, fringed 

 internally ; branchiae ovate, tuberculated. Tongue ? 



Gen. 27. Doto, Oken. Tentacles linear, long, with short, wide, trumpet- 

 shaped sheaths ; veil small, plain ; branchiae ovate, muricated. 

 Tongue narrow, with a large central spine 



Fam. 10. Proctonotidce. 



Gen. 28. Proctonotus, A. and H. Dorsal tentacles simple, linear ; veil 

 distinct, notched in front. Tongue broad, with numerous 

 smooth spines. Jaws plain 



Gen. 29. Antiopa, A. and H. Dorsal tentacles laminated, united by a 

 semicircular crest; oral tentacles with or without a veil. 

 Tongue broad, with numerous lateral spines and a central one, 

 all simple. Jaws denticulated 



TYPE. 



T. leporina, Linn. 



M. rosea, Rang. 



D. fragilis, For. 



P. mucroniferus, A. & H. 



A. cristata, Delle Ch. 



Fam. 11. Glaucidte. 



Gen. 30. Glaucus, Linn. Head indistinct ; tentacles very short ; branchiae 

 compressed, tapering, arranged on broad flattened footstalks; 

 foot very narrow, rounded in front. Tongue narrow, ivith 

 a single plate, bearing a long stout spine and marginal 

 denticles . . . . . G. Forsteri. 



b. With the posterior vessel of the gastro hepatic system above the ovary. 



Fam. 12. Uolididte. 



Gen. 31. Calma, A. and H. Body depressed, rather broad; tentacles 

 small, simple, linear; branchiae linear-fusiform, clustered on 

 cylindrical footstalks; foot broad, anterior angles acute. 

 Tongue very small and narroiv, bearing a single spine 



Gen. 32. Flabellina, Cuv. Body slender; dorsal tentacles laminated; 

 oral tentacles long ; branchiae linear or fusiform, clustered 

 on footstalks ; foot narrow, anterior angles much produced. 

 Tongue a central spine with marginal denticles, and two 

 separate plain lateral spines . . . F. affinis, Gm. ?* 



C. glaucoides, A. & H. 



* The Eolidia flabellina of Yerany belongs to this genus; his E. affinis appears to be different 

 from that of Gmelin. 



