PALUDINA,
River Snail.
Generic Character.
Testa ovata, spiralis, tenuis, umbilicata. Apertura semi-orbicularis, ad labii anterioris apicem subangulata. Operculum corneum.
Animal fluviatile, branchiatum, viviparum, rostro brevissimo; oculis ad basin externam tentaculorum acutorum 2 appositis; pedis margine antico duplici; lateribus anticè alis parvis instructis; alâ dexterâ involutâ in canalem per quem aqua in tracheam introducitur.
Typus Genericus Helix vivipara, Lin.
Shell ovate, spiral, thin, umbilicated. Aperture nearly orbicular, slightly angulated at the top of the inner lip. Operculum horny.
Animal fluviatile, branchiated, viviparous; rostrum very short; eyes placed at the external base of two pointed tentacula; anterior border of the foot double; on each side the fore part of the body a small wing; that on the right side is folded into a channel, by which the water is introduced into the respiratory canal.