TUERITELLAD^S. 121 



oval, entire. Animal with short, triangular ten- 

 tacles ; foot rounded at each end. 



T. Montagui. Fig. 182 ; n. s. 



FAMILY IX. TURRITELLAD.E. 



Shell spiral (sometimes tubular) , lengthened ; 

 upper part partitioned off ; aperture simple ; oper- 

 culum horny, many-whorled. Animal with a short 

 muzzle, eyes, and tentacles ; mantle fringed ; foot 

 very short ; gill-plume single. 



Scalaria (Lamk.). Wentletrap. Shell white, 

 polished, many-whorled; whorls rounded, sepa- 

 rated, ornamented with transverse ridges ; aperture 

 round. 



S. clathratula. S. Trevelyana, 



communis. Fig. 183 ;#. s. Turtonis. 



Grcenlandica. 



Ccecum (Fleming). Shell tubular, cylindrical, 

 curved ; aperture round ; summit closed by a 

 plate ; operculum horny, many-whorled. 



C. trachea. 



glabrum. Fig. 184; -f. 



Aclis (Loven). Shell minute, lengthened, 

 spiral ; aperture oval ; lip prominent. Animal with 

 a long retractile proboscis; tentacles close to- 

 gether ; foot truncated in front. 



A. ascaris. Fig. 185 ; f . 

 nitidissima. 

 supranitida. 

 unica. 



