GASTEROPODA. 



149 



inhabitant of these beautiful shells : — " The animal is 

 variously tinted, with tints of brown, green, white, and 

 salmon colour. The head and tentacula are brown, the 

 eye peduncles white, the eyes blue. The lateral cirrhi, 

 which thickly fringe the side lobes, are greenish brown ; 

 the side lobes themselves striped alternately with brown 

 and greenish white. The sides of the foot are dark 

 greenish brown; its disk, which is rounded at each ex- 

 tremity, of a salmon colour." 



Family 3. — FISSURELLA CEA. 



The animals of this family are symmetrical; the eyes 

 sessile. The shell is also symmetrical, always cup-shaped, 

 never operculated, and rarely absent. — Marine. 



Emarginula. Lam. — Shell rather oblong, with the 

 apex entire and curved, and having a 

 narrow ^slit or notch in the margin in 

 front ; interior smooth ; exterior with 

 raised lines in rays. Animal with a 

 short muzzle, terminating a tumid head „ . 7 



* ° m Emarginula reticulata. 



bearing two subulate tentacles with sub- 

 pedunculated eyes at their external bases; a range of 

 cirrhi around the sides at the base of the foot; mantle 

 simple edged ; anal siphon with its angulated membranous 

 sides projecting from the edges of the fissure; branchial 

 plumes two ; tongue with numerous transverse dental 

 elements; its rachis composed of nine teeth, the central 

 one laminar, and subquadrate, the lateral teeth very 

 numerous.* — 26 species; also fossil. 



* Forbes's British Moll, 

 l 3 



