Three species of Cornucoquimba Ohmert, 1968 are known from the Brazilian shelf: C. decorata, and C. nana in the north and northeast, and C. conulata in the south. An analysis of 339 samples collected between the international boundary at the Oiapoque river (Amapá State) and Cape S Roque (Rio Grande do Norte State), a distance of almost 1400 km, has discovered a new species of this genus, C. ramosae sp. nov. It is restricted to the equatorial shelf and prefers biodetrital sand, from 15 to 67 m water depth. J. Micropalaeontol. 21(1): 23-27, May 2002.