A Manual of Conchology / According to the System Laid Down by Lamarck, with the Late Improvements by De Blainville. Exemplified and Arranged for the Use of Students.

by Thomas Wyatt

1. Valvata. One species.

This genus contains shells found in fresh water. Shell sub-discoid or conoid, umbilicated, spiral whorls rounded; summit papillose; aperture round, not modified by the last whorl; the edges completely united, sharp; operculum complete, horny, and orbicular.

V. piscinalis. The Pond Valvata. Pl. [20], fig. 5.

Small, globular, conoid, deeply umbilicated; summit obtuse; wrinkled longitudinally, covered with a yellowish epidermis.

2. Paludina. Seven species.

Generally inhabits fresh water, though some have been found where it is quite saline.

Shell conoid, covered with epidermis, spiral whorls rounded; rather longer than broad, edges united, always sharp; the commencement of the left edge immediately attached to the last whorl of the spire; operculum horny, complete, or marginal, not spiral, with concentral elements.

Paludina vivipara.

P. achatina.

P. Bengalensis.