A large collection of caryophyllaeid tapeworms from catostomid fishes in eastern Texas, U.S.A. was utilized to evaluate the reliability of key morphological features that putatively distinguish between Glaridacris confusus and Glaridacris laruei. The number of testes, anterior extent of the testicular and vitelline fields, shape of the postovarian vitelline follicles, spatial relationship between the postovarian vitelline follicles and the ovary, postgonopore distance, and dimensions of the testes were all examined to determine if they correlated, as suggested in published dichotomous keys. No character was unambiguously associated with the overall morphotype of either species, and features supposedly diagnostic of one species were associated with features supposedly diagnostic of the other. The high variability among these character associations observed in the present investigation, combined with the variability reported by past investigations, suggests that new collections will be needed to clarify the species-level diversity in Glaridacris.