1909] Robherflies of the Genus Asilus 153 



and preceded on either side by several yellow bristles. Male genitalia 

 rather short, swollen, distinctly wider than the abdomen, shining black 

 in color; oviduct long and slender, about equal in length to segments 

 5, 6 and 7. 



A male from Ithaca, New York, collected by Nathan Banks, Aug- 

 ust 10, 1SS9, and a male and female from Montgomery, Massachusetts, 

 collected by Knab, August 24, 1896. 



Asilus affinis Williston (Fig. 26). 



Mystax of the male bright golden. Legs bright yellow with the 

 exception of the posterior femora which are black. Length 15 to 

 16 mm. 



Facial gibbosity prominent, mystax composed of abundant golden 

 hair. Occiput with dark hairs above and pale hairs below. Thorax 

 black, thinly clothed with dray dust, on the dorsum with numerous 

 dark more or less bristly hairs ; wings hyaline ; legs largely yellow, each 

 middle femur with a black marking above on the basal half, each hind 

 femur and apex of each hind tibia on the outer side also black. Abdo- 

 men shining black, apex of each segment with a narrow gray border. 

 Male forceps wide, excavated on the upper side at the apex. 



The male tvpe from which mv description and drawing were taken 

 are in the Francis Huntington Snow Collection at the University of 

 Kansas. This specimen is from the state of Washington. Another 

 male taken in the Santa Cruz Mountains of California by Coquillet is 

 in the U. S. National Museum. , 



Asilus fiavofemoratus n. n. (Fig. 27). 



New name for Asilus flavipes Williston which is preoccupied by 

 Asilus flavipes Wiedemann from Europe, Svst. Beschr. (1820) II, 

 325, 28. 



Shining black, front and middle femora yellow with the exception 

 of an elongate black marking above on each, hind femora black, all 

 the tibiae yellow. Length 12-18 millimeters. 



Face and front narrow, facial gibbositv prominent, but not reach- 

 ing near to the antennae, mystax of the female composed of a few 

 black hairs above and several white ones below, of the male almost 

 entirely black, but sometimes partially golden and there may be other 

 variations. Wings hyaline, very slightly gray at the apex and along 

 the posterior margin. Each femur of the forward and middle legs 

 with a black stripe above, hind femora black; all the tibiae yellow, each 

 posterior black at the apex on the outer side ; each metatarsus yellow 

 with a black apex, other tarsal segments mostly black. Abdomen 

 shining black, apex of each segment narrowly gray; upper forceps of 

 the male entire above and of about the same width throughout. 



Specimens at hand from Pa., Ohio, N. J., Va., Mass., N. Y., Ills., 

 N. C, Md. and Canada. Common in the eastern part of the United 

 States. 



