Sp . 4. Eciton rapax, n. s.

Worker.-Length 4\ lines. The head, thorax and legs of an opaque black; seven or eight of the apical joints of the flagellum fulvous beneath; the head and mandibles as in E. curvidentata; the edges of the cavity for the reception of the antennae rather more raised at the sides; the metathorax armed with two acute spines; the articulations of the legs, the apex of the tibia) and tips of the joints of tarsi, ferruginous; the first node of the abdomen having beneath a small spine curved backward: the abdomen reddish-yellow, thinly sprinkled with pale pubescence; the legs, head, thorax and antennae sprinkled with black hairs.

Worker (minor).-Very closely resembling the larger worker; the flagellum has more of the fulvous colouring; the tip of the scape, the anterior margin of the face and inner edge of the mandibles, more or less ferruginous; the legs rufo-fuscous, with their articulations as well as the tarsi ferruginous; the metathorax without spines, but having two longitudinal carinae, not produced at their termination. The first node of the abdomen armed beneath, as in the larger worker; there is also a minute tooth at the base of the second node, pointing forwards; abdomen reddish yellow.

This species was found by Mr. Bates at Para, and also at Santarem; I have not been able to find any description of it, and believe it to be a new species . It is found in the virgin forests of Brazil, as observed by Mr. Bates, not in open sandy situations like most of the other species.