108 



GASTROPODA. 



Euncina (Forbes). Minute, slug-like; mantle 

 distinct ; eyes sessile ; no tentacles ; gills three 

 plumes beneath the mantle, on the right side of its 

 hinder edge ; shell wanting. 



R.Hancocki. Fig. 151 ; f. 



DipJiyUidia (Cuv.). Oblong, fleshy; mantle 

 ample ; gills placed beneath the hind edge of the 

 mantle, on both sides ; head with a veil, and 

 minute tentacles ; shell wanting. 



D.lineata. Fig. 152 \%n.s. 



152 



Pleurdbranchus (Cuv.). Oval or roundish, fleshy ; 

 mantle covering the back and sides, and over- 

 lapping the foot ; gill a single plume, beneath its 

 right edge ; tentacles two, grooved ; a broad lobed 

 veil ; shell flexible, convex. 



P. plumula. Fig. 153 ; n. s. 

 membranaceus. 



