128 



silvery, iiicliuling the vitta, in the female grayish polliuose, the vitta 

 brownish ; orbital bristles present iu both sexes ; three postsutural and 

 two sternopleural inacroch;et;Te, thorax of male grayish pollinose except 

 on the front end, not vittate, that of the female gray liollinose and 

 marked with four black vittie ; abdomen gray pollinose, last three seg- 

 ments black on the hind margins, or each marked with three black 

 spots; length, 4 to G mm. i^orthern Illinois; Colorado, and Los An- 

 geles County, Cal. (Journ. N. Y.Ent.Soc.,Vol. Ill, p. 103; September, 

 1895.) tergata Coq. 



Genus OPSIDIA Coq. 



Opsidia Coquillett, Journal N. Y. Eut. Soc, Vol. Ill, p. 102; September, 1895. 



Our single species is black, the first two joints of the antenure and 

 the palpi yellow; three postsutural and two or three sternopleural 

 macrochiietie ; length, 9 mm. From the type specimen. Massachusetts; 

 Atlantic City, N. J., and Iowa. (Loc. cit.) gonioides Coq. 



Genus HILARELLA Rond. 



Hilarella Rondaui, Dipterologiic Italic^' Protlromus, Vol. I, p. 70 ; 1856. 

 Eumacronychia To^xnseJX^\, Traus. Amer. Ent. Soc, Vol. XIX, p. 98; May, 1892. 

 Gijmnoprosopa Tovvnseiul, loc. cit., p. 108. 



This synonymy is by the writer. All of our species have three post- 

 sutural and two sternopleural macrochaitjie : 



1. Tip of abdomen black, scutellum bearing three pairs of marginal 



macrochtetai 2. 



Tip of abdomen and the genitalia yellow, scutellum bearing only 

 two pairs of marginal macrochfetie, abdomen gray pollinose, 

 hind margins of the first three segments black, third vein bristly 

 at least halfway to the small crossvein, arista thickened on the 

 basal half; length, 6 to 8 mm. From a cotype specimen received 

 from Mr. Townsend. Las Cruces, N. Mex., and Los Angeles 

 County, Cal. (Trans. Amer. Ent. Soc, Vol. XIX, p. 99; May, 

 1892 : Eumacr onychia.) decens Town. 



2. Third vein bristly at least halfway to the small crossvein 3. 



Third vein bearing from one to four bristles near its base 4. 



3. Arista thickened on at least the basal three-fifths, abdomen gray 



j)ollinose, the first three segments each marked with from one to 

 three black spots, hind margin of the fourth segment also black, 

 antenna^ usually but not always yelloiw; length, 5 to 9 mm. 

 Franconia, N. H.; Xew Bedford, Mass.; Avalon and Angelsea, 

 N. J., and northern Illinois. From the type si)ecimen. (Jour- 

 nal X. Y. Ent. Soc, Vol. Ill, ]>. 106; September, 1895: Gymno- 



prosopa.) fnlvicornis Coq. 



Arista at most thickened on the basal two-fifths, abdomen shining 



