10. Atta instabilis ^HNS. B.M.

Worker. Length 3-3i lines.-Head ferruginous, thorax and legs more or less obscurely so; abdomen black and shining.

Head large, wider than the thorax or abdomen, finely longitudinally strigose; the mandibles striated, their teeth and margins black; the eyes and antennae black, the latter sometimes fuscoferruginous, the tip of the scape ferruginous. Thorax striated, obliquely so at the sides, and transversely so above; the metathorax with a broad deep longitudinal channel, which is transversely striated, not spined. Abdomen ovate, the nodes of the petiole rugose; the entire insect thinly sprinkled with pale pubescence.

Male. Length 3 1/2 - 4 lines.-Black and shining, pubescent: the tips of the antennae and the apical joints of the tarsi pale rufotestaceous. Head small, much narrower than the thorax, eyes prominent; the wings colourless and iridescent, with the nervures rufo-testaceous, the stigma darkest. Abdomen very black and shining.

Hab. Northern India.