DESCRIPTION. 181 



as is usual in Voluta. No species can better illus- 

 trate the plaited section which has been proposed 

 in the description of the genus Murex, than this, 

 which possesses no property in common with its 

 present congeners but its teeth. The specific name 

 is changed from Pyrum to dentatus, because there 

 is already a Murex Pyrum. 



Fig. 3, Helix distorhis. 



Shell solid, subumbilicate, striate, distorted, ob- 

 tuse at the apex 5 body gibbous ', aperture com- 

 pressed, lunate. 



Chemn. Conch. 5. tab. 160. fig. 1513. a. b. 



Specimen white, polished; striae oblique and 

 curved ; margin of the aperture thickened ; last 

 whorl produced into an obtuse projection on the 

 right side. 



Habitat unknown. 



The general appearance of the shell bespeaks it 

 a Helix, and not a Trochus as it has hitherto been 

 designated. The convexity of the columella, and 

 the upright situation and form of the aperture, ir^ 

 resistibly confirm the first impression. 



