146 Annals Entomological Society of America [Vol.11, 



yellow each with a narrow black apex, metatarsi yellow apex of each 

 black; other tarsal segments black mostly with yellow bases. Abdo- 

 men dark brown in ground color, thinly clothed with yellowish dust ; 

 posterior margin of each segment plainly lighter colored than the 

 other parts and preceded on each side by a few bristles. End lamella 

 of the oviduct wedged in. 



This is the only American species known to me with the end lamella 

 of the oviduct wedged in. Specimens from Pennsylvania, New Jer- 

 sey, Maryland, North Carolina, Massachusetts, Maine, Ohio. 



Asilus tenebrosus Williston (Fig. 5). 



Machimus griseus Hine, The Ohio Naturalist VII, 29, is a synonym. 

 There is an older Asilus griseus Wiedemann from Java, Dipt. Exot. 

 I, 192, 17. 



Male and female brownish gray with reddish legs and narrow white 

 margins at the apexes of the abdominal segments. Wings hyaline with 

 well defined dark markings in the cells at the apex and along the pos- 

 terior margin. Length 17 to 20 millimeters. 



Front and face of usual width, facial gibbosity prominent extend- 

 ing two thirds of the distance from the oral margin to the antennae; 

 mystax black above and white below; antennae black, rather long, 

 third segment of each with its style decidedly longer than the other 

 two segments combined, style about equal in length to the remainder 

 of the segment, beard white. Thorax dark in ground color but 

 clothed with gray dust which is denser in some places than in others, 

 thus giving the part a variegated appearance ; a wide mid-dorsal black 

 stripe divided anteriorly by a narrow grayish interval ; scutellum with 

 two black bristles at the apex; legs red with numerous black bristles, 

 coxae black, each femur dark on the anterior side except just before 

 the apex; wing clear hyaline with dark markings as follows: marginal, 

 both submarginal and first posterior cells each with a stripe which 

 reaches the apex of its respective cell; second posterior, discal and 

 anal cells each with an angular spot not contiguous with the margin 

 of the wing; halteres pale yellowish. Abdomen of the same general 

 color as the thorax, with a light colored annulation preceded by a row 

 of white bristles at the apex of each segment. Eigth segment of the 

 male distinctly produced below, but not with an appendage as in 

 some of the European species of the group ; male genitalia reddish in 

 color, oviduct shining black. 



Several specimens from southwestern Colorado and Huachuca 

 Mountains, Arizona; Flagstaff and AVilliams, Arizona, collected by 

 H. S. Barber; White Mountains, New Mexico, by Townshend; Pecos 

 and Beula, New Mexico, the latter place at an elevation of 8000 feet, 

 by Cockerell. 



The hyaline wings with the dark colored markings in the cells 

 as described and the wide male genitalia are sufficient to separate 

 the species from its near relatives. 



