235 



the middle, somewhat smaller and more irregular towards 

 the sides, there being about ten longitudinal rows on each 

 half; the surface is granular and the reticulations are pro- 

 duced by rows of closely approximated minute, white, tuber- 

 culate spines ; the surface between the reticulations is some- 

 what depressed ; the posterior respiratory tube is somewhat 

 thickened at the base, with a dorsal basal swelling, bluntly 

 rounded at tip, the surface coarsely granular. Length, 

 8"5 mm. ; width, 5 mm. ; height, 3 mm. 



Microdon brachycerus, n. sp. 



d . Black and ferruginous, ornamented with pale- 

 golden pubescence. Frontal stripe at vertex one-fifth as 

 wide as head, at frons half as wide as at vertex, with long 

 hairs which are yellow at sides ; face convex, prominent, 

 slightly retreating towards mouth, polished ; frons and face 

 with whitish-yellow pubescence. Antennae short and stout, 

 ferruginous, comparative lengths 3-1-16; third joint thick, 

 hardly compressed, bluntly pointed ; arista thick, shorter 

 than third joint ; the two basal joints with numerous short 

 hairs. Thorax black, margined with golden-yellow, long 

 pubescence, most conspicuous on posterior margin : a trans- 

 verse, arcuate fascia of golden hairs before the middle ; 

 pleurae w T ith long yellowish-white hairs on anterior half ; 

 scutellum prominent, with two short, stout teeth, black with 

 short black pubescence similar to that on dorsum of thorax. 

 Abdomen longer than broad, broadest at apex of second 

 segment, ferruginous and black : first segment black, second 

 dark basally and along apical margin, third darkened on 

 apical half, the very long fourth segment with two large, 

 indistinct, dark, lateral patches ; all the segments with short 

 golden pubescence, most conspicuous on posterior margin of 

 third segment. Legs ferruginous, the femora darker, fore 

 and mid femora with rather noticeable white pubescence pos- 

 teriorly ; all the tarsi thickened ; fore tarsi shorter than 

 tibiae, the joints decreasing in length, except the last, fourth 

 very short, twice as broad as long; hind tarsi similar but 

 the first joint broader than tibiae. Wing with the outer half 

 grey above the third vein, and broadly tinged with grey 

 along the cross-veins and the fourth and fifth veins, the 

 darkening produced by dense, microscopic, downy hair ; 

 stump of the third vein well developed, extending more than 

 half-way across first posterior cell ; vein closing the discal 

 cell bent strongly inward at first but finally joining the fourth 

 vein at nearly a right angle. Length, 8 mm. 



One male. Hobart, Tasmania, from ants' nest (A. M. 

 Lea). 



