138 NEW YORK STATE MUSEUM 



ee Wing with two cross bauds and the apex largely brown, these 

 bands containing hyaline spots ; apices of femora and tibiae 

 slightly darkened; length 3 mm. (New Hampshire) (com- 

 pare d y a r i) 14. discolor 



aa Wings not clouded excepting sometimes the crossvein or a faint smoki- 

 ness near the apical end 

 & Pale species 

 c Species over 3 mm. in length 



d Wholly yellowish species 15. m e 1 a n o p s 



dd Abdomen, at least of the male, with brown fasciae 

 c Thoracic stripes, metanotum, and sternum brown 



16. f 1 a Y i f r o n s n. sp. 



ee Thoracic strii)es, etc., yellow 24. n i g r o p u n c t a t a 



cc Species less than 2.5 mm. in length 



d Thorax not striped ; pale yellow species 

 e Length 1.5 to 2 mm., front metatarsus nearly as long as its tibia ; 



( St Vincent Island) 17. f 1 a v e o 1 a 



ee Length 1 mm., basal cells of wing short (D. C.) 



20. p i 1 o s e 1 1 a 

 dd Thorax with longitudinal stripes 



e Abdomen pale yellow ; the male with segments two to five with 

 a band near the base and nearly the whole of the following 

 segments pale brownish ; mouth parts brown ; R, present near 

 the tip of Ri; length 1.25 to 2.5mm. (New Mexico). (A 

 variety with yellow mouth parts from New York.) 



18. p a 1 1 e n s 

 ee Not as above ; basal cells of wing short 



f Species 1.5 to 2.25 mm. long ; abdomen brown with ashy pos- 

 terior margins to the segments ; crossveiia proximad of the 

 basal third of the wing (New York and St Vincent Island) 



19. i n d e c i s a 

 ff Species 1 mm. in length (Washington, D. C. ) 



20. p i 1 o s e 1 1 a 

 66 Darker species 



c Halteres pale fuscous ; blackish ; legs sordidly yellowish brown ; 

 tibiae long-haired ; thorax dark ; abdomen somewhat shining and 

 fuscous haired ; the R-M crossvein near the middle of the wing ; 



length 2.5 mm. (Greenland) 21. tibialis Staeger 



cc Not as above 



d Length 3 mm. ; metatarsus about 0.6 as long as the tibia ; halteres 



white 22. f a s t u o s a n. sp. 



dd Length 3.5 to 4 mm. ; halteres luteous 23. hirtipennis 



1. Ablabesmyia pictipennis Zetterstedt 

 1838 T any pus Zett. Ins. Lappon. 818. (=? T. dec e dens Walker) 

 1878 T a n y p u s O. S. Cat'l. Dipt. 22 



Female. Fiiseous black, ])iloso; the thorax with three dusky 

 stripes; the wings white, uniformly sprinkled with fuscous clouds; 

 the halteres white; the legs yellow. Length 4.5 mm. This species 



