296 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



(11) ( 



Scutellum shining black; legs very hairy.. 9. longimanus Lw., $ ?. 

 Scutellum with gray pollen; legs moderately hairy, (12) : 



n9 v ( The fan-like fringe of hairs in front of the halteres is white, (13) : 

 ' ' [ The fan-like fringe, etc., is black, (15): 



C First abdominal segment with a white cross band, occupying 



(13) 1 nearly the whole posterior margin 11. evidens n. sp., $ ? . 



/ First abdominal segment with white spots on the sides only, (14) : 



f Wings brownish -hyaline on the distal half; ungues black, reddish 



n .. j at the base only ; length 9-10 mm 12. rejectus n. sp., 9 . 



' ' } Wings almost uniformly hyaline ; ungues yellowish-white, black 



(^ at the ends only ; length 7-8 mm 13. nugator n. sp., ( $ ?) 9 . 



C Front and face broad, with a hoary bloom . .15. sudator n. sp., $ ? . 

 (15) <j Front and face rather narrow, the bloom upon them not hoary, 

 ( 14. positivus n. sp., $. 



nn (Tibiae black, (17): 



( I0 ) \ Tibiae, except the tip, red 6. aurifex n. sp., $ ? . 



n7 « i Scutellum black, shining, (18) : 



( ' ( Scutellum with gray pollen 8. cretaceus n. sp., 9 . 



f Hairs on the face black, mixed with some white (compare longi- 



| manus Lw.). 



(18) <[ Hairs on the face yellowish ; front tarsi of the male unusually 



| long; front and hind tarsi with silvery hairs on the upper side, 



[ T.princeps n. sp., $. 



1. Cyrtopogon callipedilus Loew, Berl. Ent. Zeit., 1874, 358, $ ?. 

 — Male. — Black ; thoracic dorsum with a very weak brownish pollen, form 

 ing an indistinct geminate stripe in the middle and some ill-defined 

 marks on the sides; long white pile on the face, the lower part of the 

 occiput, front part of the chest, fore coxae, and the sides of the two first 

 abdominal segments; black pile on the remainder of the abdomen and 

 the top of the head ; some scattered black hairs on the thorax above 

 aud some black hairs in the mystax above the mouth. Femora black 

 with long, soft, white pile; tibiae reddish, beset with blackish pile; tarsi 

 black, except the first joint of the four hind tarsi, which is often reddish 

 to a greater or less extent from the root ; the front tarsi, beginning 

 with the second joint, are densely beset on their upper side with recum- 

 bent, short, silvery hairs, parted in the middle ; the under side of the 

 same joints is densely beset on both sides with short, black bristles ; 

 the two last joints of the middle tarsi have on each side a dense, flattened 

 tuft of black bristles, which form together a kind of disk, which is a 

 little broader than long. Wings grayish-hyaline, more hyaline on the 

 proximal half. 



Female. — Head, and especially the face, covered with a dense whitish - 

 gray pollen; the thoracic dorsum covered with a brownish-gray pollen, 

 completely concealing the black ground-color, except at the four corners 

 and on the scutellum, which is black and shining; a geminate darker 

 line in the middle of the dorsum, not reaching the scutellum ; pleurae 

 likewise clothed with dense yellowish-gray pollen. Abdomen shining 



