171. Formica bimaculata ^HNS.

Worker. Length 2 1/4 lines.-Black and shining, with a transverse oblong white macula on each side of the second segment of the abdomen at its base, sometimes the maculae form a slightly interrupted fascia; some of the large workers have the head red. Head oblong, with the mandibles and antennae rufo-piceous; eyes rather large, prominent, and nearly circular. Thorax oblong, narrower than the head, compressed behind; the knees and the tarsi rufo-piceous. Abdomen ovate, with a few scattered glittering pale hairs; the scale of the peduncle incrassate, narrow, its margin above rounded; the legs and antennae pubescent.

The large worker only differs in being half a Une larger, and in having the head red.

Hab. St. Vincent's. (Coll. F. Smith.)