Shell aquatic, oval, turreted or conical, thin, smooth, spire pointed;
aperture oval, entire; edges disunited, the left with a very oblique
plait at the point of junction of the columella with the rest of the
margin.
Lymnæa stagnalis.
L. palustris.
L. Virginiana.
L. luteola.
L. acuminata.
L. auricularia.
L. ovata.
L. peregra.
L. intermedia.
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.