200 LAMELLARIIDiE. 



The Velutinidce are strictly marine, being met with 

 sometimes far out at sea, and at considerable depths. 

 Usually, however, they are found living on stones near 

 low-water mark. They are principally inhabitants of 

 northern seas, and are not very numerous in species. 



Sjwcies of Velutina. 



capuloidea, Blainv. laevigata, Linn. 



coriacea, Pallas. Sitkensis, A. Adams. 



cryptospira, Midd. 



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



Shell solid, semiglobose, subspiral ; aperture wide, expanded, 

 extending posteriorly beyond the apex ; inner lip oblique, re- 

 flexed posteriorly, straight and acute anteriorly. 



Caspiensis, H. and A. Adams. zonata, Gould. 



Sub-gen. velutella. Gray. 



Shell thin, flexible, pellucid, smooth, membranaceous ; spire 

 rather elevated; aperture oblong; columella flexuous. 



plicatilis, Miill. 



Fam. LAMELLARIID.E. 



Teeth on lingual membrane in three or seven series, 

 the central broad, the lateral versatile ; lateral teeth 

 simple, curved. Tentacles separated at their bases, and 

 bearing the sessile eyes at their origin externally. Mantle 

 included, lining the shell. Foot oblong, obtusely quad- 

 rate in front, rounded behind ; hind or operculigerous 



