Plauditus grandis (Ephemeroptera : Baetidae), a new small minnow mayfly from Tennessee

Plauditus grandis new species, is described from adult males and larvae col lected from Tennessee. The larvae of P. grandis are distinguished from all other North American two-tailed baetids by their large size, distinctive le g setation, narrow labial palpi, tergal patterning, mandibular morphology, absence of hindwingpads, and short median caudal filament. This species app ears restricted to the interior low plateau of Tennessee and was usually fo und with the rarely collected mayfly species, Paraleptophlebia kirchneri.