A revision of the sponge genus Neofibularia, known for its dermatitis-producing qualities, is presented on the basis of a restudy of holotypic specimens. Carter's species Fibularia massa is regarded as a synonym of N. nolitangere (Duch. &. Mich.), the only species known from western tropical Atlantic waters. A new subspecies of N. nolitangere, with oxeate megascleres, is described as well as a new species, N. mordens, from South Australia. The relationship of Neofibularia to Biemna is discussed.