A new genus, Lemaitreopsis, and a new species, Lemaitreopsis holmi, assigned to the paguroid family Pylojacquesidae are described and illustrated. The new taxa are based on a single female specimen collected from off the Isle of Pines, New Caledonia. The generic placement in the heretofore monotypic Pylojacquesidae is based primarily on the development of a median projection on the sternite of the third maxillipeds and on the calcified, posteriorly directed projection on the first pleonal sternite. Both characters are unknown in other paguroid families. Lemaitreopsis holmi is unique in the development of the external distal angle of the ischium of the third maxilliped into a very large, stout, spine-like hook.