DIPTERA. 151 



in front with some black spines beyond which it is thicklj- clothed with 

 long pale jellow and whitish hairs: eyes bronzed; fore part nearly Hat, 

 its facets larger than those elsewhere : sucker black, tawny at the tip, 

 clothed with long pale yeUow hairs ; palpi tawny, thickly clothed with long 

 pale yellow hairs and bristles, and with a few black bristles: first and 

 second joints of the feelers red, beset with short black bristles ; second 

 much shorter than the first : chest and breant ferruginous : chest beset with 

 a few black hairs and bristles, adorned u-ith four broum stripes, of which 

 the middle pair are narrow, linear and entire, the side pair broader, shorter 

 and interrupted; breast tinged with gray, clothed with tawny hairs : abdo- 

 men bright tairni/, less than twice the length of the chest, clothed with 

 tawny hairs, which are longest and most thick towards the base, pitchy 

 and obconical from the first to the third segment, narrower and linear from 

 thence to the tip which is dark red, shining and thickly clothed with black 

 hairs : legs dark red, clothed with short black hairs, armed with black 

 spines : thighs clothed with hoaiy hairs ; claws black ; foot-cushions 

 brownish tawny : ivings tawng ; wing-ribs ferruginous ; veins pitchy, fer- 

 ruginous towards the base and along the fore border; poisers tawny. 

 Length of the body 13 lines ; of the wings 20 lines. 



Rio Janeiro. 



AsiLus Gavixjs, Fem. 



Niger, thoracis vittis tribus pectore ventreque canis, capite subttts abdomi- 

 nisque segmentorum marginibux posticis albidis, anteunis uigris ar- 

 ticulo 3o basi fulvo, pcdibus nigris, tibiis apice tarsisque sublus fulris, 

 alis subcinereis ad cosfamf^tscis. 



Body black ; head adorned with a tawny covering in front, whitish 

 and clothed with white hairs behind and beneath, beset behind the eyes 

 with black bristles ; crown brown, beset with black hairs and with four 

 black bristles ; face very prominent, beset with black bristles, and towards 

 the cpistoma with long bright yellow bristles, the latter are more cluster- 

 ing than the former, and there are a few of them along the sides of the 

 peristoma: eyes bronzed; fore part flat, facets of its disk larger than those 

 elsewhere : sucker clothed at the tip with a few short pale tawny hairs ; 

 palpi beset Avith long black hairs : feelers black ; first and second joints 

 beset with black bristles, second hardly more than half the length of the 

 first ; third lawny at the base, tapering from near the base to the lip, longer 



