155 . Formica senex ^HNS. B.M.

Female. Length 4 1/2 lines.-Opake-black: abdomen slightly shining, with an obscure aeneous tinge; the mandibles, antennae and legs ferruginous; the anterior margin of the head slightly ferruginous. Head, of the same width as the thorax, slightly excavated behind; the anterior margin of the clypeus entire; the apex of the flagellum dusky. Thorax ovate, the metathorax truncate; wings subhyaline, the nervures pale testaceous; the apical joints of the tarsi dusky; the head and thorax are delicately shagreened, have a few scattered shallow punctures, and are sprinkled with erect white hairs. Abdomen ovate; the node of the peduncle ovate, margin entire; the abdomen is thinly covered with short white hairs, the margins of the segments ciliated with longer ones.

Worker. Length 3 lines.-In colour agreeing with the female. Head wider than the thorax. The thorax short, slightly narrowed posteriorly; the metathorax quadrate above and truncate behind; the scale as in the female, and the insect sprinkled with white hairs as in that sex.

Hab. Rio (Constanciae) (Coll. Rev. H. Clark.)