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372 shell is attached to a rock or wood surface by means of a calcified byssus which passes through a large notch in the right valve. The genus Pododes- mus differs in having only 2 muscle scars in the top or holeless valve. Anomia simplex Orbigny Common Jingle Shell Plate 35k Cape Cod to Florida, the Gulf of Mexico, and the West Indies. I to 2 inches in size, irregularly oval, smoothish, thin but strong. The upper or free valve is usually quite convex; the lower valve is flattish and with a hole near the apex. Color either translucent-yellow or dull-orange. Some with a silvery sheen. Specimens buried in mud become blackened. Very commonly attached to logs, wharfs and boats. Anomia aculeata Gmelin Prickly Jingle Shell Nova Scotia to North Carolina. Rarely exceeding % inch in size, irregularly rounded, moderately fragile. Upper valve convex, rough, often with small prickles. Lower valve flat and with a small hole near the hinge end. Color drab, opaque whitish tan. A. common cold-water species attaching itself to rocks and broken shells. Anomia peruviana Orbigny Peruvian Jingle Shell Plate 296 San Pedro, California, to Peru. I to 2 inches in size, variable in shape, thin, partially translucent, smooth or with irregular sculpture; colored orange or yellowish green. Occurs be- tween tides attached to rocks, other shells and waterlogged wood. Common. Genus Pododesmus Philippi 1837 The valve without the hole has i large and i small muscle scar. Pododesmus macroschismus Deshayes False Jingle Shell Plate igdi Alaska to Lower California. I to 4 inches in size. Radiating ribs very irregular and coarse. Color yellowish or greenish white, inner surface green and somewhat pearly. Lower valve with a large opening for the byssus. This is a very common species which is found attached to stones and wharf pilings from low-tide mark to about 35 fathoms. Often found on Haliotis. P. cepio Gray is a synonym. Pododesmus rudis Broderip from Florida and the West Indies is very