The genus Orthoscapheus is compared with its nearest relative Abracris, and redefined in order to include a new species, Orthoscapheus noronhensis n. sp., from the main island of the Fernando de Noronha Archipelago. This new species clearly differs in its external characters from any of the species found in the mainland, though its genitalia reveals a very close affinity with 0. rufipes (Thunberg 1824). All species in the genus are compared in tabulated form.