FUNGUS GNATS OF NORTH AMERICA. 269 



jj. Coxae in large part yellow ; one claw of each 

 foot of male modified, 

 k. Abdomen Vvith yellow fasciae- palpi yel- 

 low; tarsi of female tumid. 



15. tricincta. '^ 

 kk. Abdomen black ; palpi dark ; fore tarsi 

 about 1.75 times as long as the tibia. 



16. sciarina. 

 hh. Costa but slightly produced. 



i. Fore tarsus over twice, the metatarsus over .8 as . 

 long as the tibia, 

 j. Spurs pale. 17. dclicata n. sp. 



jj. Spurs dark. 7- gracilis n. sp. 



ii. Fore tarsus less than 1.7, the metatarsus less 

 than .75 as long as the tibia (female). 



18. obcsnla n. sp. 

 aa. Subcostal crossvein (SC2) absent. 



b. Subcostal vein ends distad of the base of Rs ; costa noticeably 

 produced; cubitus forks under or proximad of proximal end 

 of crossvein. (Compare 12. B. Hopkinsii). 3. obscura n. sp. 

 bb. Subcostal vein ends at or proximad of the base of Rs ; costa 

 but slightly produced, 

 c. Fore tarsi not over twice, hind tarsi not as long as the tibia, 

 d. Subcosta ends nearly opposite the base of Rs. 



e. Abdomen unicolored. 19. inops. 



ee. Abdominal segments with yellow posterior margins 

 (female). 19a. inops var. a. 



dd. Subcosta ends proximad of the middle of the R-M cross- 

 vein. 20. sedula n. sp. 

 cc. Fore tarsi over twice, hind tarsi longer than the corresponding 

 tibije. 21. nacta n. sp.. 



I. Boletina abdonnnalis Adams. 

 Kansas Univ. Science Bttl. II. 24. 1903. 

 Male. Length 3.5 mm. Black, subshining; head and mem- 

 bers black, except first antennal joint, which is tinged with 

 yellow, middle ocellus very small; mesonotum black, subshin- 

 ing, covered with yellow pile, which are inclined to arrange 

 themselves into rows, scutellum black, pile yellow, pleura black, 

 without ])ile, metanotum black, halteres black ; abdomen wholly 

 black, subopaque, hypopygium with a yellowish tinge, pile yel- 

 low ; legs yellowish, trochanters and tarsi, except base, largely . 

 fuscous; wings grayish hyaline, veins fuscous, subcosta joins 

 the costa opposite base of Rs, subcostal crossvein slightly be- 

 fore the proximal end of the crossvein ; furcation of the cubitus 



