"The animal of the Lymnæa genus has two flat tentacula. L. stagnalis is a very pretty spiral shell, common in ponds.
"L. auricularia is also frequent. It is much smaller than the first species. The last whorl is swelling, and the aperture very wide. They are both thin and brittle.
"The family Melaniana are chiefly foreign. The shells are covered with a dark-coloured epidermis. They are operculated.
| Melania | Helix. |
| Melanopsis. | |
| Pirèna. |
"A species of Melanopsis inhabits the river Orontes, in Syria.
"There is yet another family connected with Helix, the Peristomata, containing
| Valvata. | |
| Paludina | Helix. |
| Ampullaria | Helix, partly. |