L. leucostoma.
L. minuta.
L. stagnalis. The pond Lymnæa. Pl. [20], fig. 1.
Ovate, ventricose; spire subulate and very acute; aperture large and ovate; horn coloured.
L. leucostoma. The shining Lymnæa.
Species sub-turreted, with the right edge thickened.
FAMILY IX.
Melanides. Three genera.
1. Melania. Sixteen species.
Likewise taken from the Helix of Linnæus.
Shell fluviatile, covered with epidermis, oval, oblong; spire slightly pointed, more or less turreted; the margin of the whorls often surmounted by spires; aperture oval, entire; columella smooth and arched; closed by a thin, horny, complete operculum.