Dolichopodidae. 243 



grey pruinose ; prothoracic bristles thin, yellow. Abdomen with the 

 ground colour appearing dark or blackish grey, seen from behind 

 with a slight greenish colour, but densely silvery pruinose from the 

 base of the second segment; the first segment greenish; on the sides 

 of the second and third, sometimes also of the fourth segment, a 

 yellow translucent spot, they are sometimes small on the third seg- 

 ment, and when present on the fourth they are indistinct; abdomen 

 clothed with short, black hairs, longer at the sides, and it has long 

 hindmarginal bristles, longest on the first segment; eighth segment 

 with short hairs. Venter greyish black with the basal part yellow, it 

 has black hairs, and hindmarginal bristles; at the base there are a 

 few longer hairs in two tufts, and these hairs are black or dark 

 brown. The ventral lobes and outer lamellæ of the hypopygium 

 rather small. Legs with the coxæ grey, front coxæ yellow or a little 

 blackish at the base, posterior coxæ more or less, but generally slightly 

 yellow at the apex; femora yellow, hind femora generally blackish 

 at the tip; tibiæ likewise yellow, generally with the tip of the hind 

 tibiæ blackish; anterior tarsi blackish or brown towards the end, front 

 tarsi sometimes only blackish just at the tip, hind tarsi black; hind 

 metatarsus slightly shorter than the second joint. The legs have short, 

 black hairs ; hind coxæ with a row of only three, at most four bristles 

 on the outer side ; femora haired as in the two preceding species, but 

 the hairs still shorter and less dense; front tibiæ with bristles above, 

 middle tibiæ with two dorsal rows, and with one ventral row of small 

 bristles, the bristles of the second ventral row wanting or indistinct; hind 

 tibiæ with two dorsal rows, some almost hidden ventral bristles, and 

 with short, indistinct, bristly hairs on the dorsal and posterior side. 



Fig. 77. Wing of A. argentina cf. 



Wings a little brownish or yellowish tinged; veins blackish brown, 

 the discai bend shallow, placed nearer to the cross-vein than to the 

 apex. Squamulæ dirtily whitish with a black margin above, and a 

 yellow fringe. Balteres yellow or whitish. 



16* 



