THE OTTER SHELLS Genus LUTRARIA, Lam.
Shell oblong, gaping at both ends; cartilage plate prominent, triangular, with one or two small teeth anterior to it; pallial sinus deep, to accommodate the long, united, leathery coated siphon. Mantle closed e cept at opening for the protrusion of the strong foot; gills taper to mouth. Thirty-three species, living in sandy mud of quiet bays and in estuaries of rivers, burrowing vertically like Mya.
The Oblong Otter Shell (L. oblonga, Gmel ) has the out line of a Hollander's wooden shoe, the beak at the ankle, the broad posterior end for the toe. Out of this the great siphon pro trudes upward to clear water, while the foot ranges fifteen inches or more below in the sandy mud. The hinge is like a pivot and
works in two planes: without parting the ventral lips of the shell the gape at either end may be closed. The foot extends out through the anterior end. The long side of the body is covered with a closed mantle.
Certain Channel Islanders laboriously dig these clams in shallow water, and use them for food. As shell fish they are known as "clumps." The shells are often five inches long.
Northern Europe.
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