A taxonomic study of monozoic cestodes of the genus Glaridacris Cooper, 1920 (Cestoda: Caryophyllidea), parasites of catostomid fishes in North America, confirmed artificial character of the genus which is split to 2 different, morphologically distinct, and not closely related genera. Glaridacris is newly circumscribed to include only 3 species, Glaridacris catostomi Cooper, 1920 (type species), Glaridacris terebrans (Linton, 1893), and Glaridacris vogei Mackiewicz, 1976, which are characterized by an elongate body, a cuneiloculate or wedge-shaped scolex with 6 shallow loculi, male and female gonopores at a distance from each other, follicular ovary, and circum-medullary vitelline follicles (lateral and median). A new genus, Pseudoglaridacris n. gen., is proposed to accommodate 3 species characterized by a shorter body, a bothrioloculodiscate scolex with a pair of deeper median bothria and 2 shallower loculi, male and female gonopores close together, non-follicular ovary, and with only lateral vitelline follicles. The species are: Pseudoglaridacris laruei (Lamont, 1921) n. comb. (type species), Pseudoglaridacris confusa (Hunter, 1929) n. comb., and Pseudoglaridacris oligorchis (Haderlie, 1953) n. comb. An annotated list of all species of both genera, with data on their hosts and distribution and keys to their identification, is provided.