370 CHARLES T. BRUES. 



setacea the middle ones are placed further forward than the lateral 

 ones. The anterior pair of proclinate bristles are also relatively 

 smaller and more nearly in front of the middle pair. The costal 

 vein is much shorter in agarici and the first vein ends nearer to the 

 tip of the third than in setacea. 



The female which Aldrich described as setacea belongs to agarici, 

 while the male, which is a distinct species, stands as the type of 

 setacea. 



Aphiochieta setacea Aldrich. (Plate viii, rig. 42.) 

 Aldrich, Canadian Entomologist, xxiv, 144, figs. 



Head black, front very wide, with an ocellar prominence and median furrow. 

 All the frontal bristles large and strong, the four anterior ones proclinate. An- 

 tenna? fuscous, palpi yellow with black bristles. Dorsum of thorax clothed with 

 brownish pubescence; scutellum with two marginal bristles. Legs yellowish, 

 hind pair brownish, posterior tibiae each with a single spur. Coxae with a few 

 bristles on the outer and apical portions; the posterior coxae with a conical pro- 

 tuberance on the hind side. Hypopygiuni lying close up under the back part of 

 the abdomen. Wings slightly grayish, veins yellowish brown, costa reaching 

 nearly to the middle of the wing, provided with very long bristles. First vein 

 ending midway between the humeral cross-vein and the tip of the third, fourth 

 vein not much curved, almost straight except at extreme base and apex, seventh 

 vein distinct. Halteres yellow. 



Length 1.2 mm., of wing 1 mm. 



Type locality, Brookings, South Dakota. 



This species is closely related to the European P. rufipes Meig., 

 but lacks the peculiar bristles upon the abdomen of the male. The 

 female is very much like rufipes, and when not associated with the 

 male is almost impossible to distinguish. The costal bristles are, 

 however, a little shorter and the wing more strongly tinged with 

 yellow. Many specimens are considerably larger than the type 

 (2-2.5 mm.) 



Aphiochreta rost rata M. et B. (Plate viii, figs. 43, 44.) 

 Melander and Brues, Biological Bulletin, v, 15 (1903). 

 Female. Length 1.5-1.75 mm. — Head shining black, especially smooth and 

 polished on the front and vertex. Front with the normal ehaetoxy, except that 

 there are only two proclinate bristles at the lower edge. The front is also sparsley 

 hairy, besides the large bristles; median longitudinal groove and ocellar tubercle 

 unusually well marked. Antennae black, arista distinctly plumose. Proboscis 

 piceous, very large and strongly exserted, as long as the head height. It is 

 rather slender at the base where the rather small bristly spindle-shaped black 

 palpi are inserted, swollen and bifurcated at the extremity. The bifurcation rs 

 produced by a splhting of the apex by a horizontal slit in the probocis. Thoracic 

 dorsum shining, hairy as usual, with one pair of dorsocentral and two marginal 



