Family Selenitidie

FAMILY SELENITIDIE Shell as in Helix. Animal carnivorous; jaw without ribs ; radula well developed, rows of teeth arched.

252 The Flesh-eating Land Snails Genus MACROCYCLIS, Beck. (SELENITES, Fish.) Shell thin, spire depressed,'wrinkled, or striated; animal as in Helix; eye peduncles long; foot narrow; tail short, pointed. A world-wide genus, its centre of distribution the Pacific slope.

The Vancouver Macrocyclis (M. V ancouverensis, Lea) has five whorls coiled like a watch spring, the spire scarcely ele vated, the body whorl swollen and enlarged toward, the aperture. which is diminished in size by the flattening of the wall above it. The epidermis is yellowish green; the interior of the shell, white. The pit is wide and deep. The lip is reddish yellow, sometimes reflected.

This is one of the large snails of the Pacific slope. It lives near the coast, except where it passes the Cascade Mountains into Idaho and Montana. At Astoria it reaches its highest

development. Diameter, l I inches.

Habitat.— Alaska to Lower California.

M. sportella,

Gld., is not half the size of the preceding species, and much more delicate in structure. One requires a microscope to see the beauty of the sculpturing on its shiny, yellow-green surface. The sharp cross ridges are especially strong on the base of the shell. The pit is wide and shallow. The spire is a trifle elevated. Diameter, I inch.

Habitat.— Puget Sound to San Diego.

M. Hemphilli,

Binney, is glassy, thin, irregularly cross ridged, with no sign of spiral sculpture. The pit is very narrow. Diameter, inch.

Habitat.— Oregon and Washington.

Circinaria is an allied genus.

253