Nigrobaetis Novikova & Kluge (Ephemeroptera : Baetidae): first record and new species from southern Africa, with reassignment of one northern Africanspecies

Nigrobaetis bethuneae sp. n. (Ephemeroptera: Baetidae) is described from la rvae collected from the Cunene (Kunene) River between Angola and Namibia. T he new species represents the first record of Nigrobaetis Novikova & Kluge from southern Africa and a considerable extension of the distribution range for the genus. Nigrobaetis bethuneae is characterized by the presence of a small interantennal carina, arrangement of dorsal setae on the labrum, man dibular denticulation and setation, apicolaterally bluntly pointed labial p alp segment 3, absence of hind-wing pads, presence of the first pair of gil ls, and general abdominal coloration. Ecological data on the new species ar e provided. The Algerian species Baetis rhithralis Soldan, previously consi dered to belong in Diphetor Waltz & McCafferty, is transferred to Nigrobaet is, and the biogeographic implications of the new assignment are discussed.