Uniomerus tetralasmus shell description:

“Shell elongated with dorsal and ventral lines nearly parallel, convex to subinflated, rather thin to subsolid, inequilateral, beaks somewhat full and elevated, their sculpture consisting of six or seven moderate concentric ridges, which are evenly and rapidly rounded up behind; posterior ridge widely rounded, ending behind in a point just below the median line; on the dorsal slope there are two radiating furrows, the slope being slightly, obliquely truncate behind; anterior end evenly rounded; surface with feeble, concentric sulcations, and traces of very fine radial sculpture; epidermis yellowish-brown or ashy-brown, banded with lighter color, rather smooth, often subshining; pseudocardinals two in each valve, the upper in the right valve small, all subcompressed; laterals long, two in the left valve and one in the right; beak cavities impressed; dorsal scars immediately under the beaks; muscle scars smooth and shallow; nacre white" (Simpson, 1914; Mather, 2007).