171 



Abdomen with a large deep excavation at base of upper- 

 surface, its middle semicircularly encroaching upon middle of 

 convex portion; under-surface slightly incurved from apex to 

 base, apex encroached upon by pygidium, the latter with a 

 subtriangular fovea. Mesostemum with an acute subconical 

 process between coxae. Metasternum convex along middle, 

 but unarmed. Middle tibiae with a small subtriangular pro- 

 cess at inner apex, legs otherwise unarmed. Length, 1'75 mm. 



Hab. — Western Australia: Beverley, from a nest of a 

 small black Iridomyrmex (E. F. du B onlay). Type (unique), 

 I. 10644. 



Somewhat like A. femoralis on an enlarged scale, or 

 A. subcylindricornis on a reduced one; from both readily 

 distinguished by the armed mesosternum. From some direc- 

 tions there appears to be a feeble shining median line on the 

 head. 



Articerus duboulayi, Waterh. 

 PI. xxv., figs. 9 to 12. 



Mr. E. F. du Boulay has recently taken at Beverley 

 specimens of a species that appears to be duboulayi; they 

 differ in some respects, however, from the original description 

 and figure (it is to be noted also that the figure differs in some 

 respects from the description). In the figure the fovea on the 

 pronotum only represents its deepest part, it really occupies 

 about half the width, and more than half the length of that 

 segment. The antennae and front legs agree from some direc- 

 tions with the figure; but, as noted by Waterhouse, the 

 former look very different from other points of view. The 

 femora of the male were described as "much incrassated in the 

 middle and somewhat compressed" but they are not so figured, 

 and on the males before me it is only the middle femora that 

 are much incrassated, and they are also bidentate. The hind 

 tibiae from some directions agree with the description, but 

 from others they are seen to be armed with a tooth behind the 

 insertion of the tarsi, as a result, from some directions, the 

 apex appears bifid; the apical portion is also clothed with 

 golden hairs. The front and hind trochanters are briefly 

 dentate, the middle ones are unarmed. The metasternum is 

 ridged along the middle, the ridge becoming acute posteriorly, 

 and shortly before its apex armed with a small tooth, on each 

 side of the ridge the surface is strongly depressed. The under- 

 surface of the abdomen has a depression on each side of the 

 base, with a ridge between; between the apex of the ridge 

 and the pygidium is another depression; there are also a few 

 small fascicles. The female differs from the male in having 

 antennae shorter, straighter, and without subapical notch, 

 metasternum and under-surface of abdomen evenly convex, 



