Worker major. Length 3 lines. Head black; thorax, legs and nodes of the peduncle ferruginous; abdomen fusco-ferrugi- nous. Head enormously developed, deeply emarginate behind, with a central longitudinal channel extending to the base of the clypeus; the face striated and ferruginous anteriorly; the man- dibles and antennae ferruginous. The thorax narrowed behind, and armed with two short acute spines at the lateral angles of the verge of the truncation of the metathorax. Abdomen ovate.
Worker minor. Length 2 lines. - Head of the ordinary size, narrowed behind; the sides slightly fuscous; the insect otherwise is ferruginous; the antennae and legs more elongate than in the large worker, the thorax is also more elongate; the metathorax with two acute spines; the insect sprinkled over with short, erect, pale hairs.
Hab. Brazil (Tunantins).
