SCALARID^. 221 



Distr. — 150 sp. Mostly tropical ; Greenland, Norway, Britain, 

 Mediterranean, West Indies, China, Australia, Pacific, West 

 America. Fossil, nearl}' 200 sp. Trias — ; Britain, North 

 America, Chili, India. S. preiiosa, Linn. (Ixvi, 42). 



Shell mostlj' pure white and lustrous ; turreted ; many-whorled ; 

 whorls round, sometimes separate, ornamented with numerous 

 transverse ribs ; aperture round ; peristome continuous. Oper- 

 culum horny, few-whorled. 



Animal with a retractile proboscis-like mouth ; tentacles close 

 together, long and pointed, with the eyes near their outer bases ; 

 mantle-margin simple, with a rudimentary siphonal fold ; foot 

 obtusel}'- triangular, with a fold (mentum) in front. Sexes dis- 

 tinct ; predaceous. Dr. Gould fed them on raw beef, which they 

 eat voraciouslj?^ ; tongue armed with numerous simple ancini. 

 Range from low-water to 80 fathoms. The animal exudes a 

 purple fluid when molested. 



CLATHRUS, Oken. Shell moderately thick, whorls united, 

 longitudinal ribs numerous, aperture suboval, umbilicus covered 

 by the left lip. S. communis. Lam. (Ixvi, 38). 



OPALiA, H. and A. Adams. (Psychrosoma, Tapparone-Canefri. 

 Compsopleura, Conr.) Shell turriculated, imperforate, whorls 

 united, the last with a spiral rib at the base. S. coronata^ Lam. 

 (Ixvi, 39). 



AM^A, H. and A. Adams. Shell turriculated, thin, whorls 

 united, cancellated, with some thin irregular varices; aperture 

 semilunar, interior lip gibbous in the middle, exterior lip thin, 

 simple. S. magnijica, Sowb. (Ixvii, 45). 



ciRSOTREMA, Morch. Shell turriculated, solid, whorls cancel- 

 lated, with a few irregular thick varices ; mouth circular, outer 

 margin of aperture thickened with an externally crenulated lip. 

 S. varicosa, Lam. (Ixvi, 40). 



ACiRSA, Morch. Shell turreted, thin, whorls united, varices 

 obsolete, outer lip thin, simple. S. Eschrichtii^ Holb. (Ixvi, 43). 



FUNIS, Seeley, 1861. Shell turreted, thin ; whorls ornamented 

 with transverse laminar ribbings and usuall}^ also with spiral 

 striae, so as to produce a cancellated surface ; aperture ovate, 

 with thin margins, anteriorly subeffuse. S. elongafa, Seeley 

 (Ixvii, 46). Fossil. Cambridge Greensand ; England. Inter- 

 mediate between Scalaria and Turritella. 



CROSSEA, A. Ad. Shell turbinate, umbilicated, white ; whorls 

 convex, cancellated, simple or with varices ; aperture roundish, 

 anteriorl}^ angular, somewhat produced and canaliculated ; umbil- 

 icus surrounded and narrowed by a callus. 2 sp. Japan. S. 

 miranda, A, Ad. (Ixvii, 4t). 



ACRiLLA, A. Ad. Shell moderately thick, with very numerous, 

 equal, transverse ribbings, base distinctly keeled at the periphery, 

 outer lip thin. S. acuminata^ Sowb. (Ixvii, 48). East Indies. 



