_Head_ oblong in the _female_, rather wider than the thorax; in the _worker_ subovate and much wider; _eyes_ small, ovate and placed about the middle at the sides of the head; _antennae_ geniculated, the scape about two thirds of the length of the flagellum which is clavate, the club three-jointed; the _mandibles_ stout and dentate; the _labial palpi_ 3-jointed; the _maxillary palpi_ 4-jointed. _Thorax_, oblong-ovate in the _female_, in the _worker_ transverse in front and narrowed behind with the metathorax bidentate; the anterior wings with one elongate marginal cell and two submarginal cells, the second extending to the apex of the wing; the legs stout, the femora incrassate; abdomen ovate, the peduncle with two nodes. The insects included in this genus are undoubtedly most nearly allied to those belonging to the genus _Myrmecina_; but, excepting that they agree in having the same number of joints in the palpi, they have little resemblance to each other. With the exception of the genus _Myrmecia_, these are the largest insects in the subfamily Myrmicidae; and all the species are distinguished by their remarkably thickened femora and margined thorax: we are unacquainted with the males. 1. PODOMYRMA FEMORATA. _P._ ferruginea; capite oblongo, oblique striato, thorace abdomineque laevibus nitidis; alis subhyalinis fusco-nebulosis; femoribus valde incrassatis, basi tenuissimis, femoribus posticis infra compressis. _Female._ Length 8 lines. Rufo-testaceous; the mandibles and anterior margin of the face black, the inner margin of the mandibles rufo-piceous and armed with six short stout teeth, the apical tooth largest. The head oblong, slightly narrowed posteriorly and emarginate behind, longitudinally striated, the striae diverging from the centre at the anterior ocellus; at half the distance between the posterior ocelli and the margin of the vertex the striae are transverse. Thorax smooth and shining, with scattered fulvous hairs; the wings fusco-hyaline, with a dark fuscous stain occupying the marginal cell and traversing the course of all the nervures; the legs with the femora much incrassated, the posterior pair compressed beneath into a flattened process or keel. Abdomen ovate, smooth, shining, and with a scattered fulvous pubescence; the first node of the petiole rounded in front, narrowed and truncate behind, with a large compressed tooth beneath; the second node subglobose.