1909] Robber flies of the Genus Asilus 155 



and nearly all of the other segments. Abdomen shining black with 

 narrow gray margin to each of the segments. 



In some respects this species resembles aftinis but the extreme 

 hairiness of the head and thorax is' characteristic, while there is a dis- 

 tinct difference in the color of the legs and a certain amount of dis- 

 tinction in the male genitalia. 



Males and females collected by Coquillett in Santa Clara County, 

 California. Types in the United States National Museum. 



Asilus terminalis n. sp. (Fig. 30). 



Gray dust on the thorax more dense than most species of this 

 section of the genus, mystax in both sexes black around the outside, 

 middle part pale yellowish, upper forceps of the male genitalia not 

 excavated on the dorsal side at the apex. Length 14-17 millimeters. 



Facial gibbosity prominent, long but not reaching the antennae, 

 mystax in both sexes black above and below and with a row of black 

 bristles on either side, thus the pale yellowish central hairs are entirely 

 surrounded with black; palpi black with black hairs; antennae black, 

 first two segments with rather short black hairs; beard white, vestiture 

 of the upper part of the occiput black. Thorax with a covering of 

 gra}^ dust which largely obscures the black ground color, dorsum in 

 front with short and posterior part with longer black hairs ; scutellum 

 with a number of long black bristly hairs on its margin and with num- 

 erous shorter black hairs on its disk; wings hyaline; front leg in both 

 sexes with tibia and metatarsus, except the apex of each; and bases 

 of the other tarsal segments reddish yellow, other parts black but in 

 some specimens the apex of the femur may be narrowly yellow ; middle 

 leg the same, except there is slightly more reddish yellow at the apex 

 of each tibia and metatarsus, and the femora are entirely black in all 

 cases; hind leg black except a little more than the basal half of the 

 tibia which is reddish yellow. Abdomen black with a narrow gray 

 posterior margin to each segment and in the female especially each 

 segment is partially gray on either side. Upper forceps of the male 

 genitalia not very wide, about the same width throughout, rounded at 

 the distal end but not excavated at the apex of the dorsal side as in 

 all other western species of the same section of its genus. 



Although this species is not striking in appearance its male geni- 

 talia mark it as entirely distinct from other known western species. 



The male and female from San Antonia Canyon, near Ontario, 

 California collected July 25, 1907. 



Asilus brevicomus n. sp. (Fig. 31). 



Black, middle portion of the mystax in the male white, otherwise 

 black, in the female wholly black, hairs of the whole body decidedly 

 shorter than in coquillettii. Length 15-17 millimeters. 



Facial gibbosity long and prominent, in the male the mystax 

 above and below and a row of bristles on either side black, middle por- 

 tion white, in the female all black; front, and first two segments of the 

 antennae furnished with short black hairs, occiput with black hairs 

 above and white ones below. Thorax with short black bristh' hairs 



