Eliptio dilitata (Rafinesque, 1820)

Eliptio dilitata is one of the more common species in Missouri.  It varies in nacre color from pure white, mixed white and blue, white and salmon, blue and salmon to solid deep purple.  At some locations the color forms appear to occur in about equal numbers, although the salmon and mixed blue and salmon are the least common overall.  Not all color forms occur wherever the species is found.  For example, at the St. Francais River near Coldwater Access, the mixed blue and white form seems to be missing.

The white form of E. dilitata is sometimes difficult to distinguish from P. occidentalis, but can usually be recognized by it's longer lateral teeth.  

P. occidentalis upper, E. dilitata lower