237 



blackened, the femora and hind tibiae with a metalHc green tinge. 

 Tegula? and their ciha yellowish. Halteres yellow. Wings clear, 

 veins brown-black. All bristles black. 



Frons slightly narrowed anteriorly; face as in Figure 14, Plate 

 XIII; antenna: large, shaped as in Figure 12, the third joint very 

 distinctly pilose; palpi small, scarcely protruding. Mesonotum with 

 two rows of acrostichals ; scutellum slightly transverse posteriorly, 

 the lateral posterior corners not regularly rounded, basal bristles 

 hairlike. Abdomen normal, the surface hairs rather strong. Legs 

 stout ; fore tibia with one setula on antcro-dorsal surface at about 

 basal third, and on the postero-dorsal surface two weak setulse, one 

 at the basal fifth and the other near the middle; mid tibia with two 

 strong bristles on the antero-dorsal surface, one just before the basal 

 third and the other just before the apical third, the postero-dorsal 

 surface with two weaker bristles at about the same distance from base 

 and apex as the other two ; hind femora with the antero-ventral 

 bristles confined to the apical third; hind tibia distinctly but not 

 greatly thickened, the postero-ventral surface with four strong bristles 

 which are almost equally spaced, the first about one fifth from the 

 base, and the last very near to the apex, the antero-dorsal surface with 

 two strong bristles, the first near the basal fourth, and the other just 

 below the middle ; the anterior surface with a ciliation of short hairs 

 on its entire length; all tarsi slightly thickened, the posterior pair 

 equal in length to their tibiae, their surfaces hairy, but not conspicu- 

 ously so. Cross vein before middle of wing; costa normal. 



Length, 2.5 mm. 



Locality, Champaign, Illinois (Marten and Hart). Taken at the 

 same time and place as flavisetus. 



This species belongs to the group which includes ohliqims Loew 

 and affinis Loew. Ciliatus differs from both of these in the broader 

 face, and from affinis in the shape of the third antennal joint. 

 Wheeler's species choricits also belongs here. The color of the tegular 

 cilia in this group is not reliable as a guide to the separation of the 

 species, as in many cases it varies very considerably according to the 

 angle from which it is viewed. The large white palpi of cJioricus 

 should prove the most reliable character for its separation from 

 affinis, to which it is very closely allied. The species herewith 

 described has evidently much stronger bristling on the hind tibia than 

 either affinis or ohliquiis. 



Both sexes of choricits, taken at the same time and place as ciliatus, 

 are in the collection of the Illinois State Laboratory of Natural His- 

 tory. 



