32 ArLYSIID^E. 



Fam. APLYSIID.E. 



Teeth, central, one ; lateral, numerous, similar. Head 

 with separate, ear-like tentacles; eyes sessile on the 

 head ; mouth armed with horny jaws, and with produced 

 labial tentacles. Mantle with an internal calcareous 

 plate protecting the gill. Foot with large lateral lobes, 

 usually folded across the back. 



Shell rudimentary, internal, contained in the mantle. 



The gizzard is armed with cartilaginous plates in this 

 family ; the reproductive orifices are beneath the tentacle 

 on the right side, and the vent is dorsal, and is either 

 sessile or tubular. 



Genus DOLABELLA, Lamarck. 



Body elongated, with an oblique disk on the hind part; 

 gills concealed ; lobes of the foot not dilated for swimming. 



Shell internal, uniform, calcareous, triangular, with the 

 apex callous. 



Syn. Operculum callosum, Rumph. 



Ex. D. scapula, Martyn, pi. 59, fig. 3. Shell, D. 

 scapula, fig. 3, a. 



The Dolabellce are inhabitants of the Indian Ocean ; 

 they prefer a bottom of sandy mud, and often associate 

 together in considerable numbers ; they vary in colour 

 according to individual specimens, some being dark olive- 

 green, and others quite pink. 



Species of Dolabella. 

 ecaudata, Rang. fragilis, Lam. 



