Review of Waltzoyphius McCafferty & Lugo-Ortiz, 1995 and Zelusia Lugo-Ortiz & McCafferty, 1998 (Ephemeroptera: Baetidae)

The genera Waltzoyphius McCafferty & Lugo-Ortiz and Zelusia Lugo-Ortiz & McCafferty are revised in the present paper based on fresh and historical material, including types. New diagnostic features are presented in order to differentiate nymphs of the two species of Waltzoyphius. The adults of both species, and therefore, the adults of the genus are described for the first time. A new species of Zelusia is described, and based on the recognition of this new species, the distribution of Z. principalis Lugo-Ortiz & McCafferty appears to be restricted to a small area near the type locality. Adults of Zelusia are also described for the first time, based on the new species.