39. Polyrhachis vigilans ^HNS. Pl. IV. fig, 39. B.M.

Female. Length 4 1/2 lines.-Black: densely clothed with fine, short, silky, golden pubescence. Thorax: a short acute spine at each of the anterior angles; the posterior margin of the prothorax curved, the metathorax truncate; the legs with a thin silky pile, and sprinkled with long pale hairs. Abdomen subglobose; the scale incrassate, broad at the base and acute at its superior margin, which is widely emarginate above, the angles of the emargination acute, and a short tooth at the sides.

Hab. Hong Kong.