and placed the latter in the genus Aplexus, pointing out that in hypnorum the mantle has plain edges, and is not expanded over the shell, which has a long spire and an epidermis; while in fontinalis the mantle is lobed, expanding over the shell, which has a short spire and no epidermis. In regarding these differences as specific and not generic, we have followed Turton, Forbes and Hanley, Gwyn Jeffreys and other authorities.
Limnæa peregra. The Wandering Mud-shell.—Common in ponds and ditches.
Limnæa stagnalis. The Pond Mud-shell.—Abundant everywhere in ponds and stagnant ditches.
Limnæa auricularia. The Ear-shaped Mud-shell.—In similar situations, but much less common.
Limnæa palustris. The Marsh Mud-shell.—Generally distributed, and not uncommon in the marsh dykes, and here and there in stagnant water.
Limnæa truncatula. The Truncate Mud-shell.—In shallow ditches; fond of crawling on the half-dried mud at the sides.—B. Mr. Unwin has found it on the mud principally by the side of the Cut near Landport, where it is rather plentiful. This is the only locality, however, in which he has met with it. Mr. Weaver has noted it as a rare species in the neighbourhood of Halting. At Ratham, near Chichester, Mr. W. Jeffery has found it plentiful, as also at Lindfield.
Limnæa glabra. The Smooth Mud-shell.—Very local. In narrow grassy ditches at Albourne, Cowfold, and Henfield.—B. In a ditch near Mailing.—U. Rare in the vicinity of Brighton.—M.
Ancylus fluviatilis. The River Limpet.—On and under stones in the shallow parts of running water, and may be found sometimes on the under side of the submerged leaves of the yellow water lily, Nuphar lutea.
Ancylus lacustris, vel oblongus. The Lake Limpet.—Not so common as the last named. Mr. Borrer has found it at Cowfold adhering to shells of Limncea auricularia, and at Henfield and Albourne on the under sides of the leaves of Nymphæa alba and Nuphar lutea. Recorded as occurring in the vicinity of Lewes (U), and in the neighbourhood of Brighton (M). These so-called freshwater Limpets furnish another illustration of the fact that both salt and fresh waters have their respective representative forms.
