56 CALIFORNIA ACADEMY OF SCIENCES, [Proc. 3D Ser. 



absent on a mid-dorsal vittiform area. Abdomen elongate, laterally com- 

 pressed, dull brownish black, with the sides and venter of the first to fourth 

 segments yellow. Hypopygium not constricted at the base; posterior 

 appendages small, yellow, bristling with short hairs; anterior appendages 

 very short, blunt, black; penis yellow, rather slender, pointed, twice as long 

 as the posterior appendages and directed backwards. Pleurae greenish 

 black, opaque with gray dust. Fore coxae yellow, slightly infuscated at their 

 bases, anterior surfaces with white hairs; middle and hind coxce brown with 

 yellow tips. Legs yellow; tarsi blackened from the tip of the first joint; 

 apical half of hind femur and tip of hind tibia infuscated. Fore tibia distinctly 

 swollen; first joint of fore tarsus very short, second and third joints much 

 longer, subequal; fourth and fifth joints equal, each about half as long as the 

 third joint; third and fourth joints fringed on their upper surfaces with long 

 hairs. Hind metatarsus distinctly broader and shorter than the succeeding 

 joint. Wings gray, broad and subtruncated at the tip, much narrowed 

 towards the base, so that the hairy anal margin lies close to the sixth vein. 

 Third and fourth veins nearly parallel, the apical segment of the latter being 

 bowed forward slightly and terminating in the tip of the wing; posterior 

 cross-vein distinctly beyond the middle of the wing, not one-third the length 

 of the distal segment of the fifth vein. Tegulae and halteres yellow, the 

 former edged with brown and fringed with yellow cilia; the latter with 

 brownish peduncles. 



One specimen collected in sweepings at Buck Creek, 

 Wyoming, August 14, 1895. 



The species resembles N. fortunatus but may be at once 

 distinguished by the longer, tapering and less plumose 

 arista, by the green front, more wedge-shaped wing, the 

 subequality of the second and third joints of the fore tarsi, 

 the absence of the long bristle on the second joint, and the 

 structure of the hypopygium. 



55. Nothosympycnus nodatus Loezu. 



Plate III, Figs. 80-82. 



Several males and females in my collection agree very 

 closely with Loew's description. They were taken in damp 

 woods in the vicinity of Milwaukee and Chicago. The tip 

 of the wing of the male is more pointed than that of JV. 

 fortuntatiis, the basal portion somewhat less narrowed. 

 The posterior appendages of the hypopygium are yellow, 

 the anterior pair black, the penis yellow, delicate, extend- 

 ing backwards, but not so far as in N. Oreas. The fore 

 tibiae of the male are not incrassated. 



