From the Leonard Formation in the western part of the Glass Mountains, eleven species of fusulinids are recognized. The lowest member of the formation, member A, has Schwagerina dugoutensis n. sp., S. hawkinsi Dunbar and Skinner, S. hessensis Dunbar and Skinner, S. crassitectoria Dunbar and Skinner, S. guembeli Dunbar and Skinner, Monodiexodina linearis (Dunbar and Skinner), Parafusulina leonardensis n. sp., and P. allisonensis Ross. The middle member, member B, contains Schwagerina hessensis, S. hawkinsi?, Parafusulina spissisepta Ross, P. leonardensis, and Schubertella muellerriedi Thompson and Miller. Member C at the top of the formation has the distinctive species Parafusulina durhami Thompson and Miller.

In the shelf deposits that form the Leonard Formation in the western part of the Glass Mountains, the base of member B is believed to correlate with the Hess fossil bed in the upper part of the Hess Member of the basin deposits of the eastern part of the Glass Mountains. Member C is correlative with the beds overlying the Hess Member. Several fusulinid species from near the base of the Leonardian Series show close similarity with species from the Sterlitamak beds of the Russian Sakmarian Series and fusulinid species from higher beds in the Leonardian bear close resemblance to those from the Russian Artinskian Series.