Descrição dos adultos de Camelobaetidius billi (Ephemeroptera, Baetidae)

The adults of Camelobaetidius billi Thomas & Dominique, 2000 are described for the first time. They can be distinguished from the other known adults of the genus by the following combination of characters: in males, turbinate portion of the compound eyes orange, abdominal color pattern, and the shape and relative length of the forceps articles; in females by the abdominal color pattern. The specimens were collected at Presidente Figueiredo, State of Amazonas, Brazil, and represent the first report of the species in Brazil.