MAY FLIES AND MIDGES OF NEW YORK 191 



(/(/ Yellowish or greenish species 



e Legs pale; tibiae with black tips'; thorax and abdomen yellow; 



length 4 mm 7. fascipennis 



ce Some or all femora partly black ; nietanotum with brown vittae 



or spots ; length about 4 mm. 

 f " Metanotum marked with a transverse pair of triangular 



brown spots " 8. t a e n i a p e n n i s 



ff " Metanotum marked with a pair of brown spots which 

 approach each other posteriorly." (This may be a synonym 

 of the t a e n i a p e u n i s above) . .9. p u 1 c h r i p e n n i s 

 aa Wings unmarked, excepting sometimes with darkened crossvein 



& Dorsum of thorax and abdomen black. The former may have indis- 

 tinct stripes and the latter may have paler incisures 

 c Legs black or fuscous 

 d Thorax shining black 



e Halteres white ; wings white, immaculate ; male ; length 



2.75 mm 10. b r u n u i p e s 



ce Halteres with brown knob ; wings hyaline, very slightly smoky, 

 with anterior veins and crossvein brown ; fore metatarsus 

 nearly twice as long as its tibia ; length 3.5 mm. 



11. b r u n n e i p e n n i s n. sp. 

 dd Thorax grayish, with black stripes ; abdomen black 



e Abdomen uniformly dark brown or black ; halteres white with 



end of knob brown 12. caliginosus n. sp. 



ec Abdomen with whitish incisures or margins 



f Fore metatarsus % longer than its tibia ; halteres dark in the 

 male, paler in the female ; anterior tarsi of the male with 



long hairs 13. niveipennis 



ff Fore metatarsus % longer than its tibia 



.'/ Anterior tarsi of the male long-haired ; abdominal segments 

 with narrow white posterior margins ; wings hyaline with 



black crossvein (Greenland) 14. hyperboreus 



(j<j Anterior tarsi of the male short-haired ; abdominal seg- 

 ments with cinereous margins ; wings slightly cinereous 



15. s t' a e g e r i 

 cc Legs more or less pale 



d. Halteres with gray or black knobs 



e Femur black with yellow apical ring; tibia black and yellow; 



wings with black crossveiu 16. flavicingula 



ce Legs not so marked 



f Mesonotum and scutellum shining black 



11. b r u n n e i p e n n i s n. sp. 

 ff Mesonotum pruinose, scutellum yellowish ; length 2.3 mm. 



17. h a 1 1 e r a 1 i s 

 del Halteres with pale knobs 



c Basal joint or joints of abdomen yellow 



jf First and second abdominal segments 3 r ellow ; male 



18. n i t i d e 1 1 u s 

 ff First segment only yellow 19. f a 1 1 a x u. sp. 



