The new genus and new species Cymapamphantus valentineorum, belonging to the geocorid subfamily Pamphantinae, is described from one brachypterous male and six brachypterous females taken on Guana Island, British Virgin Islands. A dorsal habitus illustration, dorsal and lateral photographs of the male and female, diagnosis, and description of C. valentineorum are provided to help distinguish this new Caribbean bug from other New World pamphantines. A checklist of the species, keys to the three tribes and eight genera, and a color photograph of a representative species of each genus of the New World Pamphantinae are provided.