Genus Ptychobranchus

Class Bivalvia : Subclass Paleoheterodonta : Genus Ptychobranchus

Ptychobranchus fasciolaris( (Kidneyshell)
The Kidneyshell mussel has a thick, shallow, kidney-shaped, yellowish brown to brown shell that has broken green rays. It lives in the gravel of medium to large rivers. In Illinois it occurs in the drainage of the Wabash River.
Conservation status: endangered in Illinois
Taxonomy: Order Unionoida; Superfamily Unionoidea; Family Unionidae; Subfamily Lampsilinae