no 



CONCHOLOGY. 



P. angulatus. 

 P. deformis. 



P. lens.* 

 P. glabratus.* 

 P. armigerus.* 

 P. parallellus * 



P. vortex. 



P. imbricatus. 

 P. con tortus. 



P. parvus.* 



P. exacuous.* 

 P. campanulatus.'' 

 P. trivolvis.* 

 P. bicarinatus.* 



FAMILY IX. 

 Melaxiaka. Three genera. 

 1. Genus Melania. PI. X. 



Animal. See Helix. 



Shell. Turreted ; aperture entire, spire slightly pointed, mar- 

 gin of the whorls often surmounted by spires, columella smooth 

 and arched, closed by a thin horn-like operculum ; this is a flu- 

 viatile shell, often covered by a thick epidermis. Inhabits the 

 rivers of India. Many fine species are found in America. Fifty- 

 four species. 





Melania inquinata. 

 M. asperata. 

 M. spinolusa. 

 M. gronifera. 

 M. aurita. 

 M. lineolata. 

 M. trunculata. 

 M. carinefera. 

 M. truncata. 

 M. coarctata. 

 M. punctata. 

 M. subulata. 



Melania Helvetica. 

 M. lineata. 

 M. Byronensis. 

 M. sulcata. 

 M. laevigata. 

 M. clavis. 

 M. decollata. 

 M. amarula. 

 M. thiarella. 

 M. fasciolata. 

 M. laevissima. 

 M. corrugata. 



M. Troostiana.* 



M. plicifera.' 



