THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 37 



175. First antennal joint black, at least on upper edge 176. 



First antennal joint wholly yellow 191. 



176. Fore coxae yellow with a green or blackish stripe on outer posterior edge, which 



is wide above, usually tapering to a point below 177 . 



Fore coxae wholly yellow, or blackened a little at base 183. 



177. Hind femora with only one preapical bristle No. 165, penicillatus, new name. 



The main preapical bristle ending a row of increasing size 178. 



178. One or more of the orbital cUia next to the proboscis black, above these are from 



four to ten orange colored cilia, the rest all black. 



No. 160, consanguineus WTieeler. 

 Lateral and inferior orbital cilia all yellowish 179. 



179. First antennal joint long and with long bushy hair; first and second joints broadly 



yellow on inner side below; arista thickened . .No. 169, crenatus Osten Sacken.. 

 First antennal joint and arista nearly normal 180. 



180. Second as well as first antennal joint conspicuously yellow below 181. 



Second antennal joint wholly black or only a little yellow on inner side 182. 



181. Bend in last section of fourth vein very near basal third; third vein considerably 



bent backward at tip No. 158, afflictus Osten Sacken. 



Bend in last section of foiu-th vein a little nearer the middle, because the portion 

 beyond the bend is shorter; third vein not bent backward quite so much at 

 tip No. 163, idohoensis Aldrich. 



182. Bend in last section of fourth vein not further from the cross-vein than the length 



of that vein; rather large species No. 162, aurifex, new species. 



Bend in last section of fourth vein distinctly further from the cross- vein than the 

 length of that vein; rather small species No. 182, aldrichii \Mieeler. 



183. Antennae wholly black; middle femora with two preapical bristles. 



No. 173, bakeri Cole. 

 First antennal joint yellow below 184. 



184. Middle basitarsi \vithout a bristle above 185. 



Middle basitarsi with a bristle above 187. 



185. Fore tarsi yellow with the fifth joint black No. 144, discifer Stannius. 



Fore tarsi black from the tip of the first joint 186. 



186. Middle tibiae with one bristle below No. 171, slossonae, new species. 



Middle tibiae with a row of three (sometimes only two) bristles on lower anterior 



edge No. 170, harbechi, new species. 



187. Inferior orbital cilia with a prominent black bristle near the proboscis 188. 



No black bristle on the lower part of the head near the proboscis 189. 



188. Fore coxae black at base on the outer surface No. 192, scoparius Loew. 



Fore coxae wholly yellow, or nearly so No. 193, quadrilamellatus Loew. 



189. Fore tarsi yellow with the fifth joint black No. 194, laciyiiotus Coquillett. 



Fore tarsi infuscated from the tip of the first joint 190. 



190. Fore basitarsi yellowish -brown, the black at tip not sharply defined, shading 



into the yellowish color No. 196, talus, new species. 



Fore basitarsi yellow, the black at tip sharply defined, second joint usually a 

 little yellowish at base No. 197, coquilletti Aldrich. 



191 . Third antennal joint wholly black 192. 



Third antennal joint yellow, at least at base 198. 



192. Second antennal joint wholly black 193. 



Second antennal joint mostly yellow 195. 



193. Mddle basitarsi without a bristle above No. 195, occidentalis Aldrich. 



Middle basitarsi with a large bristle above •. 194. 



194. Third vein distinctly bent backward at tip No. 196, talus, new species. 



Third ^ein scarcely bent backward at tip, nearly straight. 



No. 197, coquilletti Aldrich. 



