214 Syrphidae. 



central knob bare. Epistoma narrow, ratlier flat, the central knob 

 slightly prominent. Vertex chiefly yellow-haired, frons dark brown- 

 haired; epistoma with not dense, whitish hairs. Occiput greyish yellow 

 pruinose, the hairs all yellow, Antennæ black or brownish black, 

 rather large, third joint large, about square but slightly longer than 



Fig. 107. Anlenna of P. fulviventris S, from the inside. X 85. 



broad land with the upper apical angle soraewhat produced; arista 

 thickened, scarcely as long as the antennæ. Thorax dark greenish 

 æneous or sometimes somewhat coppery, shining; it has rather short, 

 yellow hairs. Pleura with long, yellow hairs, Abdomen extensively 

 yellow as in immarginatus, the base, a narrow middle line and trans- 

 verse lines at the hind margins of second to fourth segments black, 

 fifth segment yellowish with a black middle line; the middle line is 

 broadest on second segment, and the transverse lines are a little 

 broader than in immarginatus. Abdomen is clothed with short, yellow 

 hairs, longer at the sides towards the base; on the black lines a few 

 black hairs. Venter yellowish, somewhat translucent, with longish, 

 pale hairs, short towards the end. Legs yellow, only hind metatarsus 

 and the two last joints black, the metatarsus with the apex yellow; 

 hind tibiæ may be slightly darkened about the middle. Front troch- 

 anters with inconspicuous short, yellow bristles below ; the front femora 

 with the curious, white hair at the base and with a dense ciliation of 

 long, black, somewhat curlod hairs on the posterior side; below there 

 are some yellow hairs; front tibiæ thin at the base, then suddenly 

 dilated, broadest above the middle and after it again a little con- 

 tracted; they are somewhat whitish towards the apex, below with a 

 dark longitudinal line and at the apex a couple of small, black, trans- 

 verse lines ; pubescence short, yellow, at the upper part of the posterior 

 margin a short fringe; front tarsi moderately dilated, evenly and only 



I 



