268 DIPTERA FROM SOUTHWESTERN UNITED STATES 



two antero-dorsal bristles; mid femur with two to three weak bristles at base on 

 antero- ventral surface and five to six longer bristles on postero- ventral; mid 

 tibia with three bristles on posterior surface; hind femur with two to three 

 weak bristles on basal half of postero-ventral surface, and a series of bristles 

 on antero- ventral, the apical three to five much stronger than the others; hind 

 tibia with two antero-ventral and two antero-dorsal bristles; the preapical 

 postero-dorsal bristle (calcar) not noticeably longer than upper antero-dorsal. 

 Wing-veins except costa bare; costal thorn of moderate length; outer cross- 

 vein slightly curved; apical sections of veins three and four slightly divergent. 

 Length, 6.5 mm. 



Type.— 9 , Yosemite Valley, California, May 22, 1908, [A. N. 

 S. No. 6193]. 



This species belongs to the same group as P. palpata Stein, a 

 Euiopean species, but differs in color of legs, etc, I have seen no 

 very closely allied North American form. 



Phaonia nigricauda s{>. n. 



Mal( and Female. — Fulvous, glos.s3\ Head blackish brown, back of head 

 grayish pruinose, frontal orbits and face with whitish iridescent pruinescence; 

 antennae and palpi brown, second joint of former and base of latter paler. 

 Thorax unmarked. Abdomen Avith apical half conspicuously blackened. 

 Legs fulvous, tarsi slightly infuscated. Wings clear, veins pale brown. 

 Calyptra and halteres yellow. 



Ala'e. — Ej^es with very short pul)escence, separated at narrowest part of 

 frons by a distance nearly or quite equal to width across posterior ocelli; 

 antennae reaching to upper mouth margin, third joint over twice as long as 

 second; arista long and slender, plumose, the longest hairs about equal in 

 length to width of third antennal joint; parafacials almost linear in profile; 

 cheek about as high as width of third antennal joint. Presutural acrosti- 

 chals four-rowed, the outer series on each side strongest; postsutural dorso- 

 centrals three; hj^popleura bare; posterior spiracle small, subtriangular. 

 Abdomen elongate, slighth' tapered at apex, the last two segments with 

 postmarginal and discal bristles; fifth sternite with a deep, broad, central ex- 

 cision. Fore tibia sometimes unarmed, at times with an anterodorsal bristle 

 near middle; mid femur with four to five long slender bristles on basal half 

 of postero-ventral surface; mid tibia with two to four posterior bristles; hind 

 femur with a series of widely spaced bristles on antero-ventral surface, and 

 another, weaker, on basal half of postero-ventral surface; hind tibia with one 

 to two weak antero-ventral and two stronger antero-dorsal bristles; calcar 

 short and stout. Wing-veins bare; outer cross-vein bent; apical sections of 

 veins three and four sub-parallel. 



Female.- — Eiffers from the male in having the frons one-third as wide as 

 head, the fore tibia sometimes with an antero-dorsal and a posterior bristle, 

 and the mid and hind femoral bristles weaker and less numerous. Length, 

 6 to 7 mm. 



