The Pennsylvanian gastropod Pseudozygopleura (Pseudozygopleura) from the Appalachian Basin. 2 / R.D. Hoare and M.T. Sturgeon. The Pennsylvanian gastropod genera Orthonema Meek and Worthen, and Streptacis Meek, from the Appalachian Basin / J.R. Anderson, R.D. Hoare and M.T. Sturgeon.
