TURRITELLAD^. 121 



oval, entire. Animal witli short, triangular ten- 

 tacles ; foot rounded at each end. 



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



Family IX. Turritellad^. 



Shell spiral (sometimes tubular) , lengthened ; 

 upper part partitioned off ; aperture simple ; oper- 

 culum horny, manj-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 ; n. s. Turtonis. 



GrcBnlandica. 



Coecum (Fleming). Shell tubular, cylindrical, 

 curved ; aperture round ; summit closed by a 

 plate ; operculum horny, many-whorled. 



C. trachea. 



glabrum. Fig. 184 ; ^. 



AcUs (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. /<r\ C A /"^ 



nitidissima. y^Sj * b n i_ y 



sui)ramtida. /v/ qS '^o 'v* 



umca. 





16^^^ 



!.^- 





