196. Formica esuriens ^HNS. B.M.

Worker major. Length 4 lines.-Head, thorax, legs, and scale of the abdomen, ferruginous; abdomen nigro-fuscous. Head very large, much wider than the thorax, deeply excavated behind; the clypeus with a central longitudinal carina, its anterior margin with a broad shallow notch; the mandibles of a darker colour than the head, the scape blackish, the flagellum red. The. thorax paler than the head, narrowed behind; the apex of the metathorax oblique; the tibiae and tarsi slightly fuscous. Abdomen ovate, the base more or less ferruginous; the entire insect thinly sprinkled with long erect ferruginous hairs; the scale compressed, narrow, its margin entire.

Worker minor. Length 3 lines.-Of the same colour as the larger worker; the head proportionably narrower, more elongatequadrate; otherwise, the same as the larger form.

Hab. Mexico.

This species closely resembles F. integra ^HNS, but is at once distinguished by the form of the scale of the peduncle.