Gastropoda - Prosobranchia - Pseudozygopleuridae

Alternative combination: Hemizyga (Hemizyga) inflata

Full reference: J. B. Knight. 1930. The gastropods of the St. Louis, Missouri, Pennsylvanian outlier: the Pseudozygopleurinae. Journal of Paleontology Memoir 4(4):1-88

Belongs to Hemizyga according to P. J. Wagner 2011

Sister taxa: Hemizyga (Hemizyga), Hemizyga attenuata, Hemizyga dubia, Hemizyga elegans, Hemizyga grandicostata, Hemizyga illineata, Hemizyga larga

Type specimen: YPM 12999, a shell. Its type locality is SL-1. Headwaters of Feefee Creek, north of Olive St. & west of Lindberg Blvd., 1.5 km northwest of Stratmann (Olivette), which is in a Moscovian marine shale in the Appanoose Formation of Missouri.

Average measurements (in mm): shell 8.50 x 4.25