« Shell nearly equivalve, subnacreous, with a more or less distinct tubercle in front of the resilium on the dorsal margin; ligament obsolete, cartilage internal with a large lithodesma; area obscure or none; beaks entire, valves almost closed; pallial sinus obsolete. » – W. H. Dall: “Contributions to the Tertiary fauna of Florida with especial reference to the Miocene silex-beds of Tampa and the Pliocene beds of the Caloosahatchie River”, Transactions of the Wagner Free Institute of Science vol.III part.3, Philadelphia 1895, p.533.
 

« Valves with radial and vertical undulations, gaping behind but not below… » – W. H. Dall: “Contributions to the Tertiary fauna of Florida with especial reference to the Miocene silex-beds of Tampa and the Pliocene beds of the Caloosahatchie River”, Transactions of the Wagner Free Institute of Science vol.III part.6, Philadelphia 1903, p.1514.
 

« Shell small, suborbicular, somewhat auriculately angulate at the anterior dorsal margin, inflated, thin not gaping, grayish white, with a thin brown periostracum, wrinkled near the margins; umbones prominent, median, strongly curved anteriorly. There is no fine miscroscopic granulate sculpture, but several more or less evenly spaced low radial ribs, which when worn appear white and are visible from the inside as white lines; there are also microscopic crowded concentric incremental lines. The ligament lies in a narrow groove situated well under the dorsal margin, with a rather broad lithodesma on its ventral surface. The hinge is slightly sinuous, anteriorly thickened, and toothless. The interior is pearly and the anterior muscle scar is rather small, suborbicular and near the dorsal angle, while the posterior muscle scar is near the posterior angle of the shell; the pallial sinus is rather small and not very deep.… » – Dall, Bartsch & Rehder: “A manual of the Recent and fossil marine pelecypod mollusks of the Hawaiian Islands”, Bulletin of the Bernice P. Bishop Museum vol.153, Honolulu 1938, p.217.