444 FISSURELLID.E. 



rosaceus, Reeve. striatus, Linn. 



sanguineus, Hanley. virgineus, Chem. 



speciosus, Reeve. 



Sub-order EDRIOPHTHALMA. 



Eyes sessile, or on slightly-raised tubercles on the 

 outer side of the base of the tentacles. Operculum none. 

 Shell, in the adult, symmetrical, conical, not spiral; 

 aperture not pearly internally. 



Fam. FISSURELLID.E. 



Tongue with a central median tooth, five denticulated 

 uncini, and numerous, slender, hooked laterals. Body 

 broad and conical. Head with a short, wide muzzle ; 

 tentacles subulate, with the eyes on slightly-elevated 

 tubercles at their external bases. Mantle-margin fissured 

 in front, the free edges forming an anal siphon occupying 

 the anterior fissure or perforation in the apex of the shell ; 

 gills two, symmetrical, on the back of the neck. Foot di- 

 lated, sides with the upper part furnished with a series of 

 short cirrhi or rudimentary filaments. 



Operculum none. 



Shell, in the adult, conical, symmetrical, not spiral, 

 either pierced at the apex, or more or less grooved or fis- 

 sured anteriorly ; aperture wide, not pearly within ; mus- 

 cular impression crescentic, open in front. 



The animals composing this family, like those of the 

 Scutibranch Gasteropods generally, are littoral and phyto- 

 phagous in their habits. In their lingual dention, and in 

 the sides of their foot being ornamented with cirrhi, they 



