Page:American Seashells (1954).djvu/435

Rh purplish and white. Anterior end has two very tiny purplish teeth. Beyond the ligament (posterior end) there are 5 to 6 very tiny, equal-sized teeth on the edge of the shell. Compare with B. citrinus, which is more elongate. Brachidontes stearnsi Pilsbry and Raymond Stearns' Mussel Santa Barbara, California, to Oaxaca, Mexico. /4 to I inch in length, obtusely carinate, with numerous coarse, beaded, radial ribs which bifurcate. Color brownish purple on the dorsal half, straw- yellow to brownish yellow on the flattened ventral half. Hinge on dorsal edge with about a dozen very tiny bar-like teeth. Usually found in colonies in crevices of stones. Two small clams, Lasaea cistula Keen and L. subviridis Dall, attach themselves to the byssus of this species. Do not confuse B. stearjisi with Septifer bifurcams, with which it often lives. B. multijormis Carpenter and B. adamsianus Dunker are closely related species, if not mere forms, found in the Panamic province. Subgenus Ischadiwn Jukes-Brown 1905 Brachidontes recurviis Rafinesque Hooked Mussel Plate 3511 Cape Cod to the West Indies. I to 2% inches in length, flattish, rather wide, with numerous wavy axial ribs. Color outside a dark grayish black, inside a purplish to rosy brown with a narrow blue-gray border. At the umbonal end there are 3 to 4 extremely small, elongate teeth on the edge of the shell. The anterior end of the shell is strongly hooked. This ■sas known as M. hamatus Say and has sometimes been placed in the genus Mytilus. Genus Amygdahnn Megerle von Miihlfeld 181 1 Shell thin, very smooth, often with colored, cobwebby designs. These clams build nests for themselves with a copious supply of byssal threads. Amygdaluni papyria Conrad Paper Mussel Plate 28i Texas and Maryland to Florida. I to 1% inches in length, elongate, smooth, glistening, fragile, and colored a delicate two-tone of bluish green and soft yellowish brown. In- terior iridescent-white. The ligament is very weak and thin. A. sagittata Rehder, sometimes dredged off^ Florida and Mississippi, is very shiny, ivory- white, half of each valve with fine, gray, cobwebby streaks. The umbo is reinforced inside by a very small, smooth column or rib.