Page 224 - The Freshwater Mussels of Oklahoma
P. 224
Description:
“Shell somewhat elliptical, inflated, rather solid; beaks generally flattened or
compressed, though often full in old specimens, without sculpture; posterior ridge
moderate, angular and sometimes slightly double; epidermis brownish, cloth-like in
unworn shells, not rayed; left valve with two pseudocardinals, which are often split up
into numerous radiating, nodulous lamellae, with two remote laterals, the lower the
larger; right valve with two pseudocardinals, the upper smjall and compressed, the lower
much split up, and one lateral, which is sometimes slightly double; hinge plate narrowed
and rounded in front of the laterals; beak cavities moderate, not compressed, showing
numerous dorsal scars under the hinge plate; muscle scars large, impressed, smooth, the
posterior one semicircular; nacre dull purplish. Female shell slightly inflated at posterior
base, sometimes having a slight sinuosity behind the swelling” (Simpson, 1914).
Comments:
Known only from a single locality in the state (Branson, 1969). This is a species
of the gulf coastal region from Florida to Texas. The single specimen collected in
Oklahoma undoubtedly represents an introduced specimen.
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