wheeler: AUSTRALIAN ANTS. 47 



Antennae 12-jointed, funiculus filiform, not clavate or conspicuously 

 enlarged at the tip. Thorax slender, with very distinct promesonotal 

 and mesoepinotal sutures; mesonotum small, discoidal, with distinct 

 sutures on all sides. Petiole with a short peduncle in front and a 

 large, prominent compressed ventral projection, the node rounded, 

 scarcely narrowed behind where it articulates hy means of its whole 

 posterior surface with the postpetiole. Postpetiole large, convex 

 below, separated by a pronounced constriction from the gaster, which 

 is rather short. Sting very long and well-developed. Legs long; 

 middle and hind tibiae without spurs; terminal joints of the middle 

 and hind tarsi conspicuously elongated and incrassated, with very 

 large, strongly curved, simple claws and large pulvilli. 



Female. Apterous and ergatomorphic. Head broadened in front 

 and more depressed at the anterior corners than in the worker. Eyes 

 very small; ocelli absent. Mandibles more falcate, not abruptly 

 curved at the tips, with only a few short, blunt teeth. Mesonotum 

 somewhat longer than in the worker. Petiole differing from that of 

 the worker in being much broader, with a very short and narrow 

 peduncle and lacking the ventral projection. Constriction between 

 the postpetiole and gaster much less distinct than in the worker. 

 Gaster much larger, elongate elliptical, sting somewhat smaller. In 

 other respects like the worker. 



Larva. Slender, smooth and nontuberculate, with twelve very 

 distinct postcephalic segments, the constrictions between which are 

 everywhere deep and conspicuous, even at the posterior end of the 

 body. Head short, rounded, with well-de^'eloped, slender, acute, 

 falcate mandibles, destitute of teeth. Clypeus rather long, project- 

 ing. Antennae very small. Maxillary sensillae long and prominent. 

 Head sparsely, remainder of body more densely and uniformly covered 

 with short, straight, stiff hairs or bristles. 



Genotype: Onychomyrmcv hedleyi Emery. 



The discovery of the ergatoid female of Onychomyrmex only adds 

 to our perplexity in regard to the precise taxonomic position of the 

 genus. Similar females are known to occur in a few other ponerine 

 genera, notably in Acanthostichus, Paranomopone, which I recently 

 described from .Queensland, and Leptogenys (subgenus Lobopelta), 

 but all of these, together with Onychomyrmex, belong to very differ- 

 ent sections of the subfamily, and the resemblances between them 

 seem to be due to "convergence" and not to morphological relation- 

 ship, or common phylogenetic development. The thorax of the female 

 has simply assumed the structure of that of the worker, while the 



