Polyrhachis rugifrons

Smith, F., 1860, Descriptions of new species of hymenopterous insects collected by Mr. A. R. Wallace at Celebes. (Part Formicidae), Journal of the Proceedings of the Linnean Society of London, Zoology 5, pp. 57-93 : 70

3. Polyrhachis rugifrons .

P. capite thoraceque subopacis; abdomine sericeo vestito; thoraee spinis duabus longis acutis antice ei postice armato, squamis bispinosis.

Female. Length 7 lines. Black; the head oblong, rugose, and narrowed behind the eyes; the palpi pale testaceous. Thorax: the prothorax armed on each side with a short, stout, acute spine, directed outwards; the mesothorax with a short abbreviated carina in the middle anteriorly, where it is rugose; the metathorax less rugose and with a fine cinereous pile, at each lateral angle is a short, stout, acute spine, pointed outwards; the legs slightly pilose. Abdomen covered with a fine, shining, changeable silky pile, which has a faint golden lustre; the peduncle armed above on each side with a stout, acute, slightly curved spine which is directed outwards.

Hab. Makassar.

This species is of the same size as, and closely resembles, P. sex-spinosus , but differs in not having the head armed posteriorly with spines, and also in the length and direction of the spines on the thorax and peduncle; it is also much more strongly sculptured. The worker only differs in having the thorax narrower, the sides being more parallel, but rather wider anteriorly; the sculpture is the same, as well as the pilosity.