Shell. The name Helix was given to this genus from the spiral shape of the shell, which varies much in form, but generally globular, and ventricose, conoid but never turriculated; summit generally obtuse, aperture varying much in size, sometimes very large, sometimes small, always regulated by the turn of the spire; oval, semilunar, more wide than long, edges disunited, entering little into the interior; right lip or margin thickened or reflected inwards. Inhabits the groves and woods both of America and Europe. Two hundred and three species.

2. Genus Carocolla. Pl. [X].

The Animal of this and the following genera of this family are precisely the same as in Helix.

Shell. Orbicular, more or less convex or conoidal above; the circumference or periphery angulated or keeled; aperture transverse, contiguous to the axis of the shell; the right margin or lip subangular, often toothed or plaited beneath. Inhabits dry situations in Europe and America. Twenty-two species.

3. Genus Achatina. Pl. [X].

Animal. See Helix.

Shell. Variable in form, but generally subturriculated, oval or oblong, aperture entire, the right lip sharp, never reflected, columella smooth, of which the anterior extremity is always open and truncated. Inhabits South America. Twenty-four species.