Pitar sulfureus
The overall shape is trigonal ovate. The posterior is subtruncated. There may also be a weak sinuosity of the posterior ventral margin. The anterior and ventral margins are rounded. The anterior dorsal margin is nearly straight, and the posterior dorsal margin is subconvex. The valves are equal in size and shape (equivalve), and there is no gape when they are closed. Sculpture consists of growth lines, which may be slightly raised and rib-like ventrally. The lunule is rounded, defined by a fine, shallow groove and extends 3/4 of the anterior dorsal margin. The umbo is subanterior and the beaks also point slightly to the anterior. The escutcheon is not well defined.
The exterior is white, and there may be some faint, light brown coloration dorsally. The interior is also white, and there may be golden coloration in the umbonal cavity, descending ventrally.
The ligament is external, but slightly sunken; it extends 1/3 of the posterior dorsal margin. On the left valve, there are three cardinal teeth (2a, 2b, 4b), none of which are bifid. The anterior (2a) and central (2b) teeth are joined dorsally, forming an inverted "v" shape. The posterior tooth (4b) is fused with the nymph. There is also one anterior lateral tooth (A2) on the left valve. On the right valve, there are three cardinal teeth: the anterior (3a) and central (1) teeth are not bifid, and the posterior tooth (3b) is bifid. There are also two anterior lateral teeth (A1, A3) on the right valve, as well as a fine ridge running parallel to the posterior dorsal margin. The posterior adductor muscle scar is slightly larger and rounder than the anterior adductor muscle scar. The pallial sinus is rounded, directed slightly dorsally, and extends to the posterior end of the nymph in length.