A review and reappraisal of bats of the genus Eumops (Chiroptera: Molossidae) reveals that considerable geographic variation is present in the bonneted bat, E. glaucinus; it is a complex consisting of >1 species. Bonneted bats in Florida are significantly larger than those in all other populations, and have proportionally shorter and deeper basisphenoid pits, the glenoid fossa is broadly triangular with rounded apices, and bacular shape differs from that in other populations. Additionally, bonneted bats in Florida have a broader palate than bats from populations in South America. Given these differences, the correct name for both Pleistocene and Recent Florida bonneted bats is Eumops floridanus (Allen, 1932). We found no geographic variation in Recent populations of Florida Eumops and little secondary sexual variation. We describe and review the distribution, morphometrics, systematics, ecology, and taxonomic history of the species, which is restricted to southern Florida. E. floridanus has one of the most restricted distributions of any bat in the New World and is one of the most critically endangered mammalian species in North America.