166 



NEW NORTH AMERICAN ANTHOMYIIDAE (dIPTERa) 



fypp^^^- CottonAvood Grove, Urbana, Illinois, July 20, 1917, 

 (J. R. Malloch), [Illinois]. 



Named in honor of Mr. T. H. Prison, who placed at my dis- 

 posal means of access to the spot where the species was collected, 

 and who has done some very good work in various lines of ento- 

 mology. 

 Coenosia argenticeps sp. ii. 



Male.— DiHcTi^ ivom fnmni in having tlu> ahdomcn entirely without yeUow 

 oolor at base and the fifth sternite black. 



Structurally similar to frisoni, but the tibial bristles are very much lonf?(>r 

 and more slender, the antero-dorsal and preapical hind tibial bristles being 

 very long, the former exceeding one-half of the tibial length. From orc- 

 gonensis it may be distinguished by the longer and more slender tibial bristl(>s 

 and the presence of but two distinct pairs of dorsal abdominal spots. All 

 three species have the mid and hind tarsi very long, the basal joint of the 

 mid pair being about half as long as the tibia, a character which separates 

 the group from compressa, in which the basal joint of mid tibia is less than 

 one-third of the tibial length. Length, 2 nun. 



Typc—d"; Gallatin Gounty, Montana, June 16, 1917, [Mont. 

 Exp. Sta.]. 

 Coenosia longispinosa sp. n. 



Male. — Black, subopaque, densely gray pruinescent. Frons brownish 

 black, paler in front; face, orbits and cheeks white pruinescent; antennae 

 yellow, second joint partly infuscated; palpi yellow. Thorax rather indis- 

 tinctly trivittate. Abdomen with a pair of large elongate blackish spots on 

 each tergite, which extend from anterior to posterior margin; fifth sternite 

 brownish. Legs yellow, tarsi slightly infuscated. Wings clear. 



Head higher than wide in front; frons a little less than one-third of the 

 head-width, each orbit about one-fourth as wide as interfrontalia, with five 

 l)ristles; anteimae extending four-fifths of the distance to mouth, third joint 

 not angulate at apex; arista pubescent. Thoracic bristles longer than usual, 

 acrostichals two-rowed. Abdomen slender, slightly longer than thorax, 

 bristles not as long as those of thorax; hypopygium and fifth sternite small, 

 the latter wth a deep central incision. Legs slender, the bristles on femora 

 and tibiae very long and slender, the preapical and antero-dorsal bristles 

 on hind tibiae each almost as long as the tibia. Venation as in Jhi.rico.ro 

 Stein. Length, li mm. 



Type.—d'; Grant, Colorado, August 19, 1914, (E. (\ Jackson), 

 [U. S. Biol. Surv.]. Pnratype. — 1 cf ; topotypical. 



This species has the tibial l^ristlcs much longei' than those of 

 ;iii\- other species known to me. 

 Coenosia laricata sp. n. 



Fiiiiit'c. -Black, densely i)al(' gray ])ruiiicsccn1 . Im'oiis with ycllowisli 

 uray, face and cliccks witli white, ))ruinesccnc('; anicnnae reddish yellow. 



