Page 201 - The Freshwater Mussels of Oklahoma

Partial Synonymy:
Unio tetralasmus Say, 1831, Simpson 1914; Isely 1925
Uniomerus tetralasmus (Say, 1831), Isely 1925; Murray and Leonard 1962;
Johnson 1970; Valentine and Stansbery 1971; Johnson 1980; Branson
1983; Oesch 1984; Turgeon and others 1988; Williams and others 1992;
Vidrine 1993; Watters 1995; Howells and others 1996
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, p 705).
Hosts for Glochidia:
Golden Shiner (Watters, 1994).
Comments:
Specimens from far southeast Oklahoma are considerably darker, with rougher
periostracum and distinctively different shape. These somewhat resemble U. declivis
found to the south and east of Oklahoma.

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