1909] Rohherflies of the Genus Asilus 169 



with silvery dust ; occipito-orbital bristles black ; first segment of each 

 antenna black, second large yellowish and shorter than the first, third 

 black, not quite as long as the first two together, arista slender, about 

 the length of the third segment; beard entirely white. Thorax clothed 

 with gray dust but with a mid-dorsal brown stripe narrowly divided 

 before and two spots of the same color on either side, one before and 

 the other behind the transverse suture; coxae gray, usually an elon- 

 gate blackish spot on the anterior side of each femur and extreme 

 apexes of all the tibiae and the tarsal segments blackish, otherwise 

 legs red. Wings uniformly reddish yellow all over, halteres pale yel- 

 low. Abdomen opaque black with a narrow gray band in front of each 

 incisure and in the anterior margin of each of these bands there is on 

 either side two or more bristles. 



Specimens from Douglas County, Kansas, taken in May and June 

 by E. S. Tucker. Also a specimen from Havana, Illinois, taken June 

 9, 1905. 



Asilus truquii Bellardi (Figs. 42 and 43). 



Grayish black, wings pale reddish, thorax with a distinct dark mid- 

 dorsal stripe; legs slender, femora mostly black anteriorly. Angle at 

 the middle of the superior side of each part of the male upper forceps 

 produced inward and backward until it meets and crosses its fellow 

 of the opposite side. Length 12 to 14 millimeters. 



Facial gibbosity very small, mystax composed of a few bristles, 

 some of the upper ones of which are black and the others white ; 

 antennae black, bristles and hairs of the occiput nearly all gray but 

 there may be a couple of black bristles behind either eye. Thorax 

 yellowish gray with a distinct, nearly black mid-dorsal stripe; wings 

 pale reddish all over; legs slender, femora largely black anteriorly, 

 reddish posteriorly; each tibia and metatarsus red, dark at the apex; 

 other tarsal segments in large part black, narrow base of each red. 

 Abdomen gray black with the posterior border to each segment nar- 

 rowly gray. Oviduct black, short, conical with four spines at the 

 tip above. 



Specimens from Mexico taken in August. Bellardi, Osten Sacken 

 and Williston have reported the species from various parts of the same 

 country. 



Asilus tuxpanganus Bellardi. 



Rather small dark colored species, legs black except a red interval 

 at the base of each tibia, wings with a slight smoky tinge. Length 

 11 to 15 millimeters. 



Gibbosity of the face small with a few bristles which are black 

 above and white below; face rather narrow and clothed with white 

 dust; each antenna black, first two segments with black hairs, second 

 segment shorter than the first, third slightly shorter than the first two 

 together. Arista slender and a little shorter than the third segment, 

 palpi and proboscis black, beard white. Thorax everywhere clothed 

 with silvery dust, above with two black stripes near the middle of the 



