FUXGUS GNATS 01^ NORTH AMERICA. 87 



ii. Fore tarsi robust, but not swollen below. 



j. Preapical wing cloud arises at the costal mar- 

 gin proximad of the tip of Ri. 

 k. Preapical wing cloud reaches apex of Rs. 

 1. Length 5 mm; hypopygium (Fig. 83)'. 



27. perlonga n. sp. 



11. Length 3 mm. 26. imitator n. sp. 



kk. Preapical wing cloud does not reach apex 



of Rs; length 2.5 mm. 28. polita. 



jj. Preapical wing cloud does not cover tip of 



vein Ri. 



k. Hind margin of abdominal segments 



broadly and distinctly yellow. 29. falla.v. 



kk. Hind margins of segments not broadly and 



distinctly yellow. 



I. The superior forceps with about 6 blunt 



black spines and one longer curved 

 one on each limb (Fig. 84). 



30. pectita n. sp. 



II. The Hmbs of the forceps with fewer 



spines, 

 m. Preapical wing cloud produced to 

 unite Avith a gray cloud on poste- 

 rior margin ; superior forceps with 

 3 or 4 blunt spines and a longer 

 curved one (Fig. 85). 



31. lassata n. sp. 

 mm. Preapical wing cloud abbr.eviated ; su- 

 perior forceps with one short blunt 

 spine on each Hmb. 32. lenta n. sp. 

 hh. Middle tibise each with i or 2 setse on flexor 

 surface, rarely with an additional smaller one 

 above, 

 i. Fork of the cubitus noticeably retracted proxi- 

 mad of the base of the crossvein; thorax red- 

 dish, slightly darker dorsally, margins of 

 abdominal segments broadly yellow; length 4 

 mm. 2^. propinquaf 



ii. Fork of cubitus not retracted when thorax is- 

 r reddish, 

 j. Species 4.5 mm long; preapical fascia extends 

 to Cui, apical wing cloud present ; coxae 

 and femora each with brownish spot ; inner 

 lateral side of hind tibiae each ciliate to 

 near the middle; hypopygium (Fig. 87). 



35. fatua n. sp. 

 jj. Smaller species. 



