110 CONCHOLOGY. 
P. angulatus. 
P. deformis. 
P. lens.* 
P. glabratus.* 
P. armigerus.* 
P. parallellus.* 
P, imbricatus. 
P. contortus. 
P. vortex. 
P. exacuous.* 
P. campanulatus.* 
P. trivolvis.* 
P, bicarinatus.* 
P. parvus.* 
FAMILY IX. 
Metanrana. Three genera. 
1. Genus WMelania. Pl. 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 foundin 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. 
M. Troostiana.* 
Melania Helvetica. 
M. lineata. 
M. Byronensis. 
M. sulcata. 
M. levigata. 
M. clavis. 
M. decollata. 
M. amarula. 
M. thiarella. 
M. fasciolata. 
M. levissima. 
M. corrugata. 
M. plicifera.* 
