Page:American Seashells (1954).djvu/515

Rh storms between Seal Beach and Huntington Beach. Once known as C. nobilis Reeve. Genus Saxidomus Conrad 1837 Shell large, slightly gaping posteriorly, hinge with 4 or 5 cardinal teeth in the right valve, 4 in the left. Pallial sinus long and fairly narrow. Saxidojims nuttalli Conrad Common Washington Clam Plate 31I Humboldt Bay, California, to Lower California. 3 to 4 inches in length, oblong, with the beaks nearer the anterior end; heavy, with coarse, crowded, concentric ribs. Color a dull, dirty, reddish brown to gray with rust stains. Interior glossy-white, commonly with a flush of purple at the posterior margins. No lunule. Ligament large. Valves slightly gaping posteriorly. Young specimens less than 2 inches are thin- shelled, somewhat glossy and with pretty, mauve, radial streaks on the dorsal edge, both in front and behind the beaks. A very common species which is edible. Also called the Butter Clam. Saxidomus gigantea Deshayes Smooth Washington Clam Aleutian Islands to Monterey, California. Possibly this is only an ecologic variation or an example of a geographical gradient within a species. It is similar to typical 7JUttalIi, but generally lacks the rust-stain color and rarely, if ever, develops the prominent concentric ridges. This is the commonest and best food clam in Alaska. Subfamily DOSINIINAE Genus Dosinia Scopoh 1777 Subgenus Dosinidia Dall 1902 Dosinia elegajis Conrad Elegant Dosinia West Florida to Texas and south. 2 to 3 inches in length, circular, compressed, glossy, straw-yellow with numerous even, concentric ridges (20 to 25 per inch in adults). Moderately common. Do not confuse with D. discus. Dosinia discus Reeve Disk Dosinia Plate 38-0; figure 81 c Virginia to Florida, the Gulf States and the Bahamas.