THE VENUS CLAMS AND CARPET SHELLS - FAMILY VENERIDAE.
Bivalves whose tropical forms are remarkable for elegance of shape, finish and coloration, frequently with chevron-shaped markings; texture very hard. A large family in tropical and tem perate zones. The genera are variously arranged by authors who disagree.
Genus VENUS, Linn.
Shell thick, ovate, smooth, ridged or cancellated; margins minutely crenulated; cardinal teeth, three; ligament prominent, lunu]e distinct; mantle margin fringed; siphons unequal, separated; fringed, foot slim. A world wide genus.
The Round Clam or Clam (V_ mercenaria, Linn.) is the "Quahog" and "Little Neck," the chief commercial clam of our east coast. In Chapter I. of Part IV. this species is fully described as a typical bivalve. The obliquely round shells are familiar in the markets.
When the tide goes out the clam-digger may be seen in the mud flats and in shallow coves raking the clams to fill his boat or basket. He has a special tool called a "clam rake." It is not a romantic enterprise — "clamming" in the quagmires of Cape Cod or elsewhere, but it is profitable. The men usually wear high boots and do not mind wading in the clinging mud. Flat-bottomed boats are used in shallow water.
"Outside clams" with thinner shells, but of the same species, 347 The Venus Clams and Carpet Shells are found on sandy bottoms of bays, or off exposed coasts. These are taken by rakes or by tongs such as oystermen use. The clam mer goes out in a boat for them.
"Treading clams" is a method used in warm waters of the southern shores, where the gigantic variety, Mortoni, reaches six inches in diameter, and a weight of five pounds. The bare
feet of the wading man range under the surface of the sandy mud, and rout out the individual clams one at a time.
The young clams of the typical species are almost as ten der and fine flavoured as oysters. Adult specimens are tougher. Var. Mortoni is tough and coarse and too strong in flavour to be a popular shell fish except to people who have known no better clams. They are used extensively for chowders on the Florida coast.
The northern hard-shell reaches three inches in length and a width of two and a half inches. It ranges from Nova Scotia to the West Indies. The season lasts from April to September, coinciding with the oyster's closed season. Clams live a long time out of water, if kept cool, and are shipped in quantities in the shell to mid-continental cities.
Sub-genus CHIONE, Megerle The Venus (V. cancellata, Linn.) is one of the very abundant bivalves on the west coast of Florida. Narrow elevated ridges cross on the surface of the valves, which range in colour from white to cloudy yellow and brown. The white lining is tinged with violet. Length, 1 to 1 inches.
Habitat.— Cape Hatteras to West Florida..
Chione includes also two or three compact little cross-barred clams on the west coast.
Genus CYTHEREA, Lam.
Shell ovate, smooth, thick; hinge with three cardinal teeth; siphons united half-way.
The Japanese Cytherea (C. petechialis, Lam.) is handsomely painted with brown chevrons and obscurely rayed on the neutral, 348 The Venus Clams and Carpet Shells olive ground. Over the smooth, white shell substance is laid a shiny epidermis, like a coat of lacquer. It is brittle and, scaling off, removes all the colour. Length, 2 to 4 inches.
Habitat.— Japan Sea to Indian Ocean.
The Convex Cytherea (C. convexa, Say) is a smooth little round clam, with a convexity behind its prominent beaks. Length, 2 inches.