The Wolfcamp Series in the Glass Mountains, TEX., is represented by a sequence of diverse litholgies and includes a regional unconformity. A detailed study of these strata reveals that two formations can be recognized in the field and that both units are within the "Zone of Pseudoschwagerina". Each formation has a distinct and characteristic fusulinid fauna. The Nealranch formation embraces the upper part of beds originally called Wolfcamp by Udden (1917) in the Wolf Camp Hills and is renamed to retain this widely used name for the time-stratigraphic unit, the Wolfcamp Series. The Lenoxhills formation unconformably overlies the Nealranch formation and is the upper formation of the Wolfcamp Series in the Glass Mountains. It was in part included in the Wolfcamp formation of King (1931), where it crops out in the western Glass Mountains and is now known to be present across the southern escarpment of the eastern Glass Mountains, and is the lower 200 to 300 feet of the Hess formation of Udden (1917). The correlation of these stratigraphic units with strata in other regions is determined on the basis of their fusulinid faunas.