HORSEFLIES OF THE SUBFAMILY TABANINAE 59 
Type.—Female, in the British Museum. 
Type locality.—Mexico. 
Distribution.—Arizona, Mexico. July 17 (Pinaleno Mountains, 
Ariz.) to July 25 (Horse ‘Camp Canyon, Ariz.). In the United States 
National Museum, 21 females, 6 males. 
This species superficially resembles 7’. abactor Philip, but differs in 
having pilose eyes, enlarged first antennal segment, black on basal 
portion of third antennal segment, and no spot at furcation. The 
writer has seen a specimen compared with the type of erythraeus by 
EK. E. Austen. This species should not be confused with Tabanus 
erythraeus Bigot from Argentina, described in the same paper but 
on page 687. The latter has been synonymized with 7’. monochroma 
Wiedemann by Kréber (17). 
Soe. 
2h 
Figure 17.—Antenna, front view of head, and palpus of (4) Tabanws erythraeus and 
B) T. orbicallus. 
Tabanus rubescens Bellardi (not Macquart) from Oaxaca has been 
considered a synonym of erythraeus (Bigot), but the writer is in- 
clined to doubt it. He has seen a series of one female and five males 
from Cuernavaca that are very close to erythraeus, but the abdominal 
spots are slightly yellower and less extensive, there is black medianly 
on the abdomen, and the male palpus is blunt apically. It would 
seem more probable that this is rwbescens Bellardi. 
TABANUS ORBICALLUS Philip 
(ia a festa Le (grec 3) 
Tabanus orbicallus Philip, Canad. Ent. 68: 157-159, 1936. 
Rather small; dusty grayish, with three rows of pale spots on abdomen; iegs 
uniformly yellowish; eye pilose; no distinct ocellar tubercle; frons broad and 
widened above. 
Female.—Length 18-15 mm. Eye with rather sparse, short pile, green blue, 
with one rather broad purple band. Frons yellowish brown, grayer just above 
and below median eallus, about three times as high as width at basal callus, 
widened above; basal callus chestnut brown to black, subquadrate, convex, not 
quite touching eyes; median callus of same color, elliptic, narrowly joined to 
basal callus; sometimes a small, brownish, denuded spot at vertex, but no ocellar 
tubercle; subeallus with thin yellowish-brown pollen over a concolorous surface. 
First two antennal segments orange brown, with black hair, the first not en- 
larged; basal portion of third orange basad of the blunt dorsal angle, black 
beyond it, the dorsal excision shallow; annulate portion about as long as basal 
portion. Clypeus and genae white, with white hair. Palpus cream colored, 
with white hair and sometimes a few black hairs, the second segment distinctly 
swollen basally, tapering to a narrow apex. 
Mesonotum gray, with an indication of paler stripes in usual pattern and a 
mixture of white, golden, and black hair; prescutal lobe orange brown. Pleura, 
sternum, and coxae yellowish brown, with long white hair, the pleura partially 
grayish. Wing hyaline; venation normal. Legs almost uniformly yellowish 
brown, the tarsi and apex of fore tibia darker. 
Dorsum of abdomen blackish, with a median row of slender gray triangles 
and large, oblique, yellowish-brown triangles at each side; venter yellowish 
brown with some gray. 
