Arkansas Fatmucket

Outline elliptical to oblong ovate, slightly to moderately inflated, anterior end rounded; sexually dimorphic with posterior end somewhat pointed in males, broadly rounded to truncate in females. Valves thin to moderately thick. Umbos moderately full, slightly projected above the hinge line. Periostracum somewhat shiny, yellow to yellowish tan, color rays lacking but lines of tiny pits running down the shell may appear to be rays. Nacre usually white, sometimes pink to iridescent; pseudocardinal teeth somewhat thin but well developed, lateral teeth well developed, interdentum thin. Length to 150 mm. (Johnson 1980; Gordon and Harris 1985; Harris and Gordon 1990)