_Animal._ Body creeping, elongated, snail shaped, having a shell placed on the posterior extremity; four tentacula, the two longest with their eyes at their tips; respiratory organs behind. _Shell._ Very small, external, ear-shaped, apex absolutely spiral, aperture very large and oval, left edge sharp and rolled inward behind. Inhabits the middle provinces of France. Two species. Testacella Haliotidea. T. Neritoidea. 4. Genus _Parmacella_. Pl. X. _Animal._ Body creeping oblong; middle of the back moderately convex, and shield-shaped; hind part in form of a tail, laterally compressed, acute above; shield ovate, fleshy, adhering at its posterior part, free before, enveloping a shell, with a notch in the centre of its right margin; four tentacula, two posterior largest; respiratory organs, under the notch of the shield, placed between the two tentacula of the right side. _Shell._ Ovate, left margin broad and reflected; right margin reflected at top and acute beneath; very thin and pellucid, of a pale yellowish-brown. Inhabits the gardens of Europe. Two species. Parmacella Olivieri. P. Cuvierii. 5. Genus _Onchidium_. Pl. X. _Animal._ Body oblong, creeping, marginated on all sides; head projecting, the lower part with a prominent margin, two retractile, cylindrical tentacula; two auriform appendages, nearly lateral; mouth beneath, destitute of maxillary processes; respiratory orifices distinct, under the extremity of the body. Destitute of a shell. Inhabits the gardens of Europe. Two species. Onchidium Typhæ. O. Peronii. FAMILY VII. COLIMACEA. Eleven genera. 1. Genus _Helix_. Pl. X. _Animal._ Of a slightly variable form, the mantle forming at its free edge a kind of ring or thick collar, especially in front, and faintly divided into two lips; foot oval, plane, smooth beneath, inflated and granular below, joined to the visceral club by a narrow peduncle; head sufficiently distinct; anterior tentacula very evident and inflated at top, the posterior very long; the mouth a vertical cleft provided with two labial lobes, a sort of marginal tooth, with a small, oval, lingual club. _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.