New Genera of Upper Paleozoic Terebratuloids

Six new genera of terebratuloid brachiopods from Mississippian and Permian strata are described and figured. The new genera are Gacina with G. cooperi, n. sp., as genotype, Afilasma with A. beecheri, n. sp., as genotype, Lowenstamia with L. texana, n. sp., as genotype, Pakistania with Dielasma biplex Waagen as genotype, Alwynia with Dielasma vesiculare de Koninck as genotype and Timorina with Notothyris minuta Broili (non Waagen) as genotype. All of the available information regarding the internal characteristics of these forms is considered and diagrammatic reconstructions and idealized serial sections are presented.