Formica atriceps

Smith, F., 1858, Catalogue of the hymenopterous insects in the collection of the British Museum. Part VI. Formicidae., London: British Museum : 44

147. Formica atriceps . B.M.

Worker major. Length 5 lines.-Ochraceous, with the head black: in some examples the head and disk of the thorax are more or less fusco-ferruginous. Head very large, much wider than the thorax and deeply emarginate behind; the clypeus with a central longitudinal carina, its anterior margin broadly and deeply notched; the mandibles armed with five blunt teeth; the flagellum ferruginous. Thorax rounded in front, compressed and much narrowed behind. Abdomen ovate, narrower than the head; the scale ovate, rounded and somewhat narrowed above; the insect is sprinkled thinly with long erect ferruginous hairs.

Worker minor. Length 4 lines.-Of the same colour as the large worker, but with the head narrower and more elongate; the clypeus, mandibles and flagellum ferruginous, otherwise resembling the large worker.

Hab. Brazil (Para; Santarem; Rio).

A specimen from the collection of Mr. Swainson, probably the female of this species, is of the same colour as the worker: the thorax ovate, with a dark stain on the mesothorax in front and an elongate dark stripe on each side; the wings hyaline, the nervures yellow; the scale of the peduncle ovate, with a slight notch above; the knees, tarsi and apical segments of the abdomen fuscous.