The differences and similarities of the genera Orthoprosopa and Paratropidia and the existing cladogenetic problems in their classification are discussed. The distinction between the genera is retained, despite the apparent paraphylety of Paratropidia. Paratropidia pacifica n. sp. is described from New Caledonia. The species belongs to a common group together with P. alex Thompson and P. margarita Thompson. The male genitalia of O. grisea (Walker), P. bilineata (Walker), and P. pacifica are figured.