April, 1911.] New Species of Diptera of the Genus Erax. 
3°9 
die and directed outward, hypopygium much narrower than in 
stramineus, clothed with black and white hair, and distinctly 
notched at the apex. 
Female abdomen uniformly yellowish pollenose and clothed 
with pale hairs, ovipositor about four millimeters in length, 
equivalent to the last three abdominal segments. 
Specimens of both sexes taken in Clark County, Kansas, by 
Dr. F. H. Snow. 
As has been stated the species has much the appearance of 
rapax, but the somewhat stouter form, the white mystax and 
beard and much slenderer hypopygium designate it as wholly 
distinct from that species. 
Erax truncatus n. sp. Thorax yellowish-brown, above, abdo- 
men gray, first four segments with long white hair, legs black 
with the exception of the basal part of each tibia which is light 
reddish. Total length 22 to 30 millimeters. 
Mystax and beard white, ocellar, occipito-orbital and a trans- 
verse row of bristles on the dorsum of the prothorax black, palpi 
black with black and white hairs intermixed, dorsum of the 
thorax, and the scutellum with many black hairs and bristles but 
there are some white ones intermixed, wings hyaline. 
First segment of the male abdomen with long white hairs on 
each side, second, third and fourth segments with long silvery 
hair parted at the middle and directed outward, fifth, sixth and 
seventh segments silvery white pollenose but without long hair; 
hypopygium rather large, from dorsal view about as wide as the 
last segment of the abdomen, from side view most prominent 
near middle above and cut off at tip so as to give a truncate 
appearance. 
First seven segments of the female abdomen silvery white, 
ovipositor slender, shining black, about seven millimeters in 
length. 
Several specimens from the Huachuca Mountains, Arizona, 
July 28, 1907. 
The large compact hypopygium of the male and the long ovi- 
positor of the female give this species a distinct appearance which 
makes its separation from others easy. 
Erax pallidulus n. sp. A pale colored species with black legs 
and hyaline wings. The male has the hypopygium small and, 
from dorsal view, very narrow. Total length, 18 to 28 millimeters. 
Mystax very pale yellowish, beard white, palpi black with 
white hair, occipito-orbital and ocellar bristles mostly black; 
thorax dorsally pale yellowish gray with short black hair anteri- 
orly and black and white bristles and hairs posteriorly, scutellum 
with pale hairs and bristles, legs black, except bases of tibiae 
which are pale, wings hyaline. 
