Page 232 - The Freshwater Mussels of Oklahoma

Partial Synonymy:
Lampsilis capax (Green), Isely 1925
Description:
“Shell round to somewhat oblong, greatly inflated, and thin (young) to moderately
thick (adults). Anterior and posterior ends rounded. Umbos greatly inflated, elevated,
and turned inward. Beak sculpture of a few faint ridges, visible only in young shells.
Small posterior wing present in young mussels. Surface usually smooth and very shiny.
Periostracum rayless, yellow, yellowish tan, or olive, becoming dark brown in older
individuals. Length to 5 inches (12.7 cm).
Pseudocardinal teeth thin, compressed, and elevated; two in each valve. Lateral
teeth thin and greatly curved; two in the left valve, one in the right. Hinge line S-shaped.
Beak cavity very deep. Nacre white, sometimes tinged with pink or salmon” (Cummings
and Mayer,1992).
Comments:
At this time, no voucher specimens of this species from Oklahoma have been
located. Isely (1925) reported the species from the Kiamichi River at Roby. Branson
(1963) reported to have found the species from the Verdigris River, two and one-half
miles east of Lenapah, Nowata County, Oklahoma. And, finally, Shepard and Covich
(1982) using information from Donovan (1979) reported P. capax from Fort Gibson
Reservoir. However, subsequently, Branson (1984) made the following statement:
“Isely reported P. capax (Green 1832) from the Kiamichi River, Branson from the
Verdigris River, and Shepard and Covich from the Neosho River; the species has also
been reported from the Arkansas River system in Kansas. All these records are probably
based upon inflated females of P. purpurata.” Until further evidence is found, this
species is not considered a part of Oklahoma’s mussel fauna.

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