BULLAD^. 109 



Family II. Aplysiadje. 



Shell rudimentaiy, internal, thin, oblong, convex, 

 slightly rolled at one end ; head distinct, with 

 tentacles and eyes ; foot long, extending behind ; 

 sides expanded into wing-like lobes, tui'ned up 

 over the back ; gill-plume concealed beneath the 

 shell, in the middle of the back. 



Aplysia (Gmelin). Sea-hare. Lengthened, ele- 

 vated in the middle ; head distinct, with four 

 rolled, ear-like tentacles ; mouth armed with horny 

 jaws; tongue-teeth 13 — 1 — 13. Dischar2:e a purple 

 fluid. 



A. punctata,* Fig. 154 ; | n. s. 



154 155 



Family III. Bullad^. 



Shell globose or cylindrical, rolled like a scroll, 

 with a minute spire, and a large aperture ; outer 

 lip sharp ; no operculum ; animal more or less 

 investing the shell ; head broad, flat, without dis- 

 tinct tentacles ; foot furnished with two side-lobes 

 and a hind-lobe ; gill single, covered by the shell ; 

 food animal. 



* The name " hyhrida " of Sowerby, adopted by Forbes and 

 Hanley, involves an absurdity, and should be rejected. 



