LITTORINAD.E. 



119 



Family VIII. Littorinad^. 



Sliell spiral, snail-like, never pearly; aperture 

 rounded ; entire ; operculum horny, few-wliorled. 

 Animal witli a tliick muzzle, eyes, and tentacles ; 

 gill-plume single ; tongue long, with a central 

 series of broad, hooked teeth, and three oblong, 

 hooked spines on each side; sides plain; foot 

 grooved at the sides. 



Liitorina (Ferussac). Winkle. Shell thick, 

 pointed, few-whorled ; outer lip sharp ; pillar flat- 

 tened, not perforated. 



177 



178 



179 



180 



181 



182 



Lacuna (Turton). Shell thin ; aperture crescent- 

 shaped ; an umbilical fissure. 



L. crassior. 

 pallidula. 



L. puteolus. 



vincta. Fig. 178 ; n. s. 



