11. Polyrhachis laevissimus ^HNS.

P. niger, laevis nitidusque; metathorace bispinoso, petioli squamula quadrispinosa, pedibus ferrugineis.

Worker. Length 2 3 / 4 lines. Black, very smooth and shining; the legs ferruginous, with the coxae, articulations, and the tarsi black. The thorax not flattened above, or margined at the sides; the division between the pro- and mesothorax distinct, that between the meso- and metathorax not discernible, the latter with two erect acute spines; the scale of the petiole with four short acute spines. Abdomen globose.

Hab. Aru.

This species is very like P. mucronatus ^HNS; on close examination, however, it is seen to be very distinct: it may be at once distinguished by its larger head, which is wider than the thorax, rounded behind the eyes, and widely emarginate behind.