40. Polyrhachis tyrannicus ^HNS. Pl. IV. fig. 29. B.M.

Worker. Length 3 lines.-Black: covered with a thin, silky, pale golden pile; the thorax flattened above and gradually arched to the apex of the metathorax, the lateral margins sharp and slightly recurved, the anterior angles armed with a stout acute tooth; the scale of the abdomen incrassate at the base, narrowed to the superior margin, which is transverse, and has an acute spine at each lateral angle, and a shorter acute one beneath at the side. Abdomen subglobose, the insect sprinkled with a few erect, pale hairs.

Hab. China.

This species may probably be the worker of P. vigilans ^HNS, but the armature of the scale is too widely different to justify their being united.