370 cAVVLiJyjp.. 



septum with an impressed groove at the columellar margin, 

 edge of septum incised internally. 



excisa, Phil. plana, Say. 



exuviata, Nutt. squama, Brod. 



glauca, Brod. uncata, Mke. 



Lessonii, Brod. unguiculus, Sow. 



pedum, M'orch. unguiformis, Lam. 



o 



Sub-gen. ergjua, H. and A. Adams. 



Shell depressed ; apex lateral ; internal lamina flat, produced 

 anteriorly, with a tubular rib at the columellar margin. 



plana, Adams and Reeve. Walshi, Herm. 



Fam. CAPULIDvE. 



Tongue-membrane winged on each side in front, teeth 

 arranged in seven series (3*r3), central teeth small and 

 broad, with the apex hooked, the lateral teeth long and 

 hamate. Rostrum lengthened ; tentacles subulate, with 

 the eyes on bulgings at their outer bases. Mantle simple 

 in front ; gill forming a single plume placed obliquely 

 across the mantle-cavity, laminae elongate, linear, partly 

 exposed. Foot folded on itself, the sides simple, ante- 

 riorly thin and strap-shaped, posteriorly thick, orbicular, 

 and concave. 



Operculum none. 



Shell limpet-like ; apex sub.spiral, in the young, re- 

 gularly spiral ; aperture with the interior simple ; mus- 

 cular impression horse-shoe shaped. 



These animals are said to feed on the sea-weed that 



