AiiTll. NOTES ON NEARCTIC BIBIONID FLIES McATEE. 5 



black species (females sometimes brown), body opaque, occiput, and 

 abdomen with rather long black hairs; long, slender, hind femora 

 and tibiae clavate; hind metatarsus swollen (in male), about as long 

 as next three joints together. Length of wing, 7-9 mm. 



The known range of this species extends from Quebec and South 

 Dakota to Georgia, Louisiana, and Colorado. 



UNIDENTIFIED SPECIES. 



PLECIA BIMACULATA Walker. 



Plecia himaculata Walker (Francis), Insecta Saundersiana, vol. 1, Diptera, 

 1856, p. 422 [United States]. May be a Dilophus. 



PLECIA LONGIPES Loew. 



Plecia longipes Loew (H.), Neue Fliegengattungen, Berl. Ent. Zeitsch., vol. 

 2, 1858, pp. 109-110 [New Orleans]. May be the same as P. heteroptera 

 Say. 



Genus BIBIODES Coquillett. 



KEY TO SPECIES. 



A. Thickened portion of costal margin extending about halfway from stigma to 



apex of wing ; femora conspicuously swollen, antennae shorter f emorata. 



AA. Thickened portion of costal margin extending much more than halfway 

 from stigma to apex of wing ; legs less robust ; antennae longer. 



B. Halteres yellow; tarsal joints slender halteralis. 



BB, Halteres dark, at least apically ; tarsal joints somewhat swollen aestiva. 



BIBIODES AESTIVA Melar.der. 



Bibiodes aestiva Melandee (A. L.), The Dipterous Genus Bibiodes. Bull. 

 Amer. Mus. Nat. Hist., vol. 21, art. 27, Oct. 1, 1912, pp. 338-340 [Wasn- 

 ington, Idaho, Montana, Wyoming]. 



Male. — Head and body shining black, with sparse, rather long, 

 pale hairs; coxae and femora of same color and vestiture; anterior 

 tibiae piceous, spurs rufous; anterior tarsi usually black, but tibiae 

 and tarsi of posterior legs more or less yellowish or rufous, the joints 

 darker apically, sometimes appearing banded ; knobs of halteres dark, 

 stalks pale; wings hyaline, stigma and veins near costa dark brown, 

 remainder merely yellowish. Length of wing, 3.5-4 mm. 



Specimens examined are four male paratypes from Lewiston and 

 Craig's Moimtain, Idaho (Aldrich). 



BIBIODES FEMORATA Melander. 



Bibiodes f emorata Melandeb (A. L.), Bull. Amer. Mus. Nat. Hist., vol. 21, 

 p. 340 [Austin, Texas]. 



Male. — Brownish black, shining, with plentiful, rather long, pale 

 hair; spurs of front tibiae rufous; halteres pale fuscous; wings 

 hyaline, stigma and veins near costa brown, remainder merely yel- 

 lowish fmnose. Length of wing, 3.5 mm. 



313G— 22— Proc.N.M. Vol.60 27 



