38 BULLETIN 116, UNITED STATES NATIONAL MUSEUM. 



195. Anterior femora with a few long, delicate, black hairs above near their base. 



No. 198, ■pJumosus Aldrich. 



Hairs on upper edge of fore femora at base scarcely longer than those on the 



remainder of the upper edge 196. 



196. Hind margin of mng rather deeply notched at tip of fifth vein. 



No. 209, dujplicatus Aldrich. 

 Hind margin of wing not or but little notched at tip of fifth vein 197. 



197. Bend in last section a little beyond its basal third No. 207, tenuipes Aldrich. 



Bend in last section of fourth vein a little before its middle. 



No. 206, canaliculatus Thomson. 



198. Hind coxae blackened on outer surface of basal half or more, at least with a 



large blackish spot covering most of basal half 199. 



Hind coxae yellow, still the outer surface sometimes has blackish streaks or 

 spots : 207. 



199. Middle basitarsi with a large bristle above 200. 



Middle basitarsi without a bristle above 201. 



200. Third vein bent backward a little so as to approach fourth at tip in an even 



curve No. 210, grandis Aldrich. 



Third vein less bent at tip, nearly or quite parallel with fourth at tip. 



No. 211, superbus, new species. 



201. Hind margin of wing deeply notched at tip of fifth vein 202. 



Hind margin of wing not or but little indented at tip of fifth vein 203. 



202. First antennal joint rather long for a female No. 181, latipes Loew. 



First antennal joint short, of the usual length for a female. 



No. 175, caroUnensis, new species. 



203. Anterior tarsi yellowish with the fifth joint black 204. 



Anterior tarsi more or less infuscated from the tip of the first joint 205. 



204. Tip of third antennal joint black No. 206, canaliculatus Thomson 



Antennae wholly yellow No. 212, ruficornis Loew. 



205. Middle tibiae a little blackened at tip No. 109, hastatus Loew. 



Middle tibiae whollj^ yellow, not infuscated at tip 206. 



206. Front and thorax with thick yellowish pollen, western . .No. 207, tenuipes Aldrich. 

 Front and thorax with thin grayish pollen, shining, eastern. 



No. \Sl,/ulvip€s Loew. 



207. Last section of fourth vein bent at an obtuse angle without a stump 208. 



Last section of Jourth vein bent at a right angle or nearly so, with a stump at 



the bend ; middle basitarsi with a large bristle above 219. 



208. Middle basitarsi with a large brietle above 209. 



Middle basitarsi without a bristle above 215. 



209. Humeri more or less yellow, at least the lower edge yellow. 



No. 179, scapularis Loew. 

 Humeri wholly metallic 210. 



210. All tarsi yellow, the anterior pair may have the last joint a little darkened. 



No. 212, ruficornis Loew. 



Hind tarsi more or less infuscated from the tip of the first joint, at least the tips 



of the joints darkened 211. 



211. Fore tarsi black or infuscated from the tip of the first joint. 



No. 180, domesticus, new species. 



Fore tarsi with the first joint wholly yellowy sometimes darkened from the base 



of the second joint 212. 



212. Fore tarsi black or blackish from the middle of the third joint, the black being 



rather sharply defined 213. 



Third joint of fore tarsi wholly yellow or yellowish 214. 



