The genus Palaeagapetus Ulmer (Trichoptera, Hydroptilidae, Ptilocolepinae) is revised in North America. Descriptions of the western species, P. nearcticus Banks 1938, are provided with the first descriptions of the female, pupa, larva, egg and case and with notes on food, habitat and annual life cycle. The male and female of the eastern species, P. celsus Ross 1936, are described or redescribed with some ecological notes. Distributions of the two species are summarized.