6o CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



anteriorly; scutellum steel-blue; abdomen shining black with greenish reflec- 

 tions; venter piceous. Pleurae above dusted with yellowish dust, below with 

 a thin layer of white dust. Fore coxae and trochanters yellow, the former 

 more or less infuscated proximally, with short yellowish hairs. Middle and 

 hind coxae and trochanters black, dusted with white like the lower pleurae. 

 Legs yellow, the fore tarsi, knees of the hind legs and the hind tarsi from the 

 tip of the first joint, black. Middle legs with the femur moderately, the tibia 

 strongly incrassated. The latter is flattened, twisted and deeply excised at 

 its distal end. From the hollow of the excision a pedunculated knob pro- 

 jects forward when the leg is in the walking position. Middle femur ciliated 

 on its lower side with rather feeble black bristles; the bristles on the middle 

 tibia are arranged as follows: first, a series of feeble, blunt bristles on the 

 lower (inner) surface, terminating beyond the middle with a few powerful 

 bristles, and at the apex with several medium-sized bristles; second, a series of 

 bristles, rapidly increasing in length, on the upper surface. Those which 

 terminate this series are extremely long and powerful. Beyond the middle 

 on the anterior surface of the tibia and proximal to the projecting knob there 

 is a dense patch of short black spines. Middle metatarsus incrassated, mod- 

 erately bent and terminating in a scoop-shaped projection. A row of regular 

 and powerful bristles runs along its whole concave surface. Remaining tarsal 

 joints plain. The middle legs are blackened from the patch of spines to the 

 end of the tarsus, the transition from the yellow to the black on the tibia 

 being very abrupt. Wings grayish hyaline. Their costal and posterior bord- 

 ers are nearly parallel. There is a slight trace of infuscation in the little 

 depression on the distal segment of the fourth vein. Halteres yellow. Teg- 

 ulas brown with black cilia. 



Five male specimens taken at the following localities in 

 Wyoming in July and September: Lusk, Little Wind 

 River canons, Hunter's Creek, Jackson's Lake. Also one 

 male and four females from South Dakota, April 14, 1890, 

 collected by J. M. Aldrich. The male of this species is 

 very readily recognized by the projecting pedunculated 

 knob on the remarkably incrassated middle tibise. 



60. Campsicnemus (Edipus, sp. nov. 



Plate IV, Fig. 114. 



Male. Length 2 mm.; length of wing 2.5 mm. Face very narrow, cov- 

 ered with ochre-yellow dust. Antennae black, third joint small, pointed. 

 Front shining black, with a bluish reflection. Postocular cilia black above, 

 yellow below. Thorax, scutellum and abdomen shining black, the scutellum 

 with bluish, the abdomen with bronze reflections. Pleurae black with pale 

 dust. Coxae black, the fore pair yellowish towards their tips. Fore legs 

 black, with the distal half of the femur and the basal half of the tibia yellow 

 or piceous. Middle tibia and metatarsus incrassated, the former twisted, the 



