THE EAR SNAILS FAMILY AURICULIDAE. Genus AURICULA, Linn.
Shell spiral, cone-shaped, usually solid, stout to slender; internal partitions usually absorbed; aperture ear-shaped, strongly defended by teeth; lung present; head bears snout and two dilated buccal lobes; teeth very small, numerous ; upper jaw semi-lunar, horny; eyes sessile on bases of tentacles; mantle thickened at mar gin, closed; respiratoryorifice posterior, on right side; sexes united.
Nearly all of this family have the habit of absorbing the internal coils of the shell, and using the material to thicken the remaining parts. The soft parts necessarily lose their spiral form when their support is gone.
The lung is actually a spongy mass of air sacs, not merely a hollow pouch. These amphibious mollusks require nearness to sea. The large and brilliantly coloured species are tropical, centring in the Pacific Islands.
The Midas's Ear (A. auris-Mida, Linn.) is heavy, elongated, with polished, golden brown epidermis covering the pale, cancel lated surface. The white or creamy lining is thickened all around the aperture, and usually raised in two folds near the base of the columella. The reflected callus often overlies the small umbilicus. A fold almost amounting to a varix indicates the last place where growth was resumed. Length, 3 to 4 inches. New Guinea.
Genus CASSIDULA, FCr.
Shell solid, square-shouldered like Cassis, last whorl large; outer lip thickened and strongly toothed; columella bears sharp toothed folds; aperture narrow.
287 The Ear Snails C. angulifera, Petit, has its angled shoulder outlined with a white band, on a ground of pale chestnut or chocolate. The animal walks on the submerged beach when the tide is in, or scrambles over arching mangrove roots, and among stones back from the water line, indifferently terrestrial and aquatic in its habits. The slim tentacles bear eyes at their bases. The foot is cleft behind. Length, i to i inches.
Habitat.— Australia.
Genus SCARABUS, Montf. (PYTHIA, Bolt.) Shell oval, laterally compressed, forming two series of varices on the conoidal spire; umbilicus rimate; aperture narrowed by thickened, strongly folded and toothed lips; outer lip much expanded. Terrestrial mollusks living in dark places in woods
near shore, coming out after rains. Eggs are laid on tree trunks.
Habitat.— Tropical islands in Old World.
Habitat.— Molucca Islands.
Genus MELAMPUS, Montf.
Shell ovate-conical, spire short, blunt; aperture narrow, both lips crossed by several toothed folds. A widely distributed genus, chiefly tropical, living on rocks or on the rank growths above tide water, where they are dashed with salt spray. They seem intermediate between marine and terrestrial forms.
The Coffee Melampus, (M. coffea, Linn.) is larger and paler than a grain of coffee, and spirally three-banded with white on its fawn-coloured body whorl. Deep in the narrow aperture is a thick white callus with about twenty cross ridges opposite the columella which bears a small ridge at the anterior end of the sharp peristome, and a much larger white fold considerably higher up. Indians used to string and wear as beads this little West Indian ear snail, which is rarely found on the gulf side of Florida. Length, / inch.
288 The Ear Snails M. bidentatus, Say, is the commonest salt marsh snail on the Atlantic and Gulf coasts. It climbs the marsh grasses at high tide as if to escape a ducking. The white cross folds deep in the outer lip and two tooth-like folds on the columella are characteristic of them all. The shells are thin and horn-coloured, broadly ovate, square shouldered, polished and often banded when young. Adult shells are corroded and coated with muddy deposits. Length, I inch.
Habitat.— New England to Texas in salt marshes.
M. olivaceus, Cpr., is a plump oval shell, smooth, dirty white banded or splotched with purple, under an olive green epidermis. The aperture is white, with sharp cross folds within the outer lip, and a single central lamina prominent on the col umella. Length, / inch.
Habitat.— San Diego, Cal.
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