Chapter XXVI: Section II: APLYSIOIDEA.--Shell small, usually not spiral, sometimes

absent, no cephalic disc, head prominent, with two pairs of tentacles, epipodia large, more or less reflected.

FAM. _Aplysiidae._--Characters those of the section. Genera: _Aplysia_ (Fig. 287 D), shell arched, flattened, animal large (the “sea hare”); _Dolabella_, shell subtriangular (Fig. 286 F); _Dolabrifer_, shell sub-quadrangular, not spiral; _Notarchus_, shell microscopic, spiral; _Phyllaplysia_, body very depressed, oval, no shell.