This shell is large, thick, compressed, asymmetrical,
inequivalve, length is slightly greater than its height, and its outline
is suboctahedral. In young specimens, the folds on the shell are
relatively higher than those of more mature animals. This
species is found in the upper division of the Buda Limestone, Austin,
This specimen is suffering from efflorescence of salts often referred to as 'Byne's disease' . It is now housed with measures to stabilize the humidity.