Female. Length 4 1/2 lines.-Black: the antennae and legs fusco-ferruginous, the joints of the legs and the tarsi palest. Head longitudinally and strongly striated; the mandibles curved, of nearly equal width, their apex rounded, their inner margin denticulate; the clypeus slightly depressed in the middle, with the anterior margin slightly emarginate. Thorax ovate; the prothorax, mesothorax, and the base of the metathorax, striated longitudinally, the truncation of the latter transversely striated; the node of the abdomen transversely striated and subglobose; the first and second segments longitudinally and more finely striated than the head and thorax, the following segments smooth, shining and rufo-piceous.
Worker.-Rather smaller than the female, similarly sculptured except the second segment of the abdomen, which is only striated at the base, the apical half being smooth and shining.
Hab. Rio. (Coll. Rev. Hamlet Clark.)
