Papuanatula, n. gen. (Ephemeroptera : Baetidae), is described from New Guinea and New Britain and based on both larvae and adults. Larvae of Papuanatula are distinguished by having basally narrow and distally broad antennal scapes ; glossae shorter than paraglossae ; segment 3 of labial palps more convex laterally than medially ; ventral long, somewhat robust, simple seta subdistally on tarsi ; gills on abdominal segments 2-7 ; reduced medial caudal filament ; and absence of hindwingpads. Adults have double marginal intercalaries in the forewings, lack hindwings, and males possess a sclerotized process between the genital forceps. Five new species are described from New Guinea [P. bessa n. sp., P. copis n. sp., P. lenos n. sp., P. plana n. sp., and P. tuber, n. sp. (type species)] and one new species named from New Britain (P. vaisisi n. sp.). An identification key to the larvae of the six new species is included.