186 



POPULAR CONCHOLOGY. 



Beck divides this genus into eleven genera, and Albeit 

 into six. 



Cylindrella. Pfeiffer. (Siphonostoma 

 Sivain.)- — Shell with the spire excessively 

 long, pointed, but the upper portions de- 

 ciduous ; aperture circular, spreading ; the 

 lips united and detached from the adjoining 

 whorl. Animal not differing outwardly 

 from that of Helix. — 45 species. 



From the West Indies and Mexico : 

 curious little shells, easily distinguished by 

 the peculiar aperture which is detached from the adjoin in 

 whorl. 



Beck divides the genus into three, and Albers 

 into eight genera. 



Megaspira. Lea. (Pyrgelix Beck.) — Shell 

 Pupiform, remarkable for the length of the spire, 

 consisting of twenty, line, close-set, narrow, gra- 

 dually increasing whorls ; the outer lip simple, 

 slightly thickened ; the inner has a tooth on the 

 body whorl, and two folds on the columella.* 

 Animal unknown. — Few species. 



Very singular shells, of which M. ( Pupa) elatior 

 is the type. ,r "" 



Bale A. Prideaux. — Shell "spiral, turreted, concen 

 trically striated, sinistral, and covered with a thin 

 brown epidermis ; spire composed of numerous 

 whorls, gradually increasing in size ; aperture small, 

 sub-quadrate; peretreme entire, slightly thickened, 

 with a very slight fold on the columella; axis per- 

 forated.! Animal very like that of Helix. — 3 species. 



* Sowerby's Conchological Manual. 



t Sowerby. 



