Ellipse and Bleedingtooth
Both species are very similar in appearance. Shell is small, relatively thick, elliptical to elongate, compressed to moderately inflated with a bluntly pointed (ellipse shown) to acutely rounded (bleedingtooth) posterior end and a thicker anterior end (ellipse). Umbo is low and slightly raised above hinge line. Epidermis is yellowish-brown to brown in adults with many fine dark green rays. Inside shell beak cavity is shallow; pseudocardinal teeth triangular, heavy and roughened; lateral teeth short, thick and straight to slightly curved; teeth sometimes rusty-red; nacre (lining) bluish-white and often tinged with rusty salmon.
Similar species: Juvenile muckets are shorter, stouter and uniformly thick and lack the fine rays. Brokenray is shorter, more rounded and thinner and females often have an indentation in the posterior margin.