140 MISC. PUBLICATION 305, U. S. DEPT. OF AGRICULTURE 
moderately broad at base, the dorsal angle distinct, but dorsal excision not 
very pronounced; apical portion about equal in length to width of basal 
portion. Clypeus and genae yellowish gray, with concolorous hair. Second 
palpal segment moderately stout, but not strongly swollen basally, yellowish 
brown, with black hair. Proboscis black, short, but little longer than palpus. 
Thorax mostly black or very dark brown, with brown hair; humeral and 
prescutal lobes orange brown; mesonotum rather shiny, the pollinose lines not 
very distinct. Wing hyaline, with brown veins, the costal cell weakly infus- 
cated; venation normal. Legs dark orange brown, fore femur, basal half of 
hind femur, apical half of fore tibia, and fore tarsus black; hind tibial 
fringe black. 
Abdomen above orange brown, With a narrow, median, black stripe widening 
on tergite 4; tergites 5-7 mostly black; each tergite with a narrow posterior 
margin of yellow pollen and hair; venter orange, with concolorous hair, the 
apical sternites blackened. 
Male.—Unknown to the writer but, according to Hine, “The male is like 
the female. The antennae are red with the exception of the apical portion 
of the third segment, which is more or less black. The frontal triangle is 
covered with silvery pollen.” 
FIGURE 67.—Antenna, front view of head, and palpus of (A) Tabanus captonis and 
(B) T. oklahomensis. 
Type—Female, lost. 
Type locality —California, | 
Distribution.—British Columbia to California and Montana. June 
(Los Angeles, Calif.) to August 27 (Chenook Pass, Wash.). In the 
United States National Museum, 18 females. 
Hine studied the type of 7abanus recedens Walker, 1854, which 
is a homonym of that described by Walker in 1848, and found it to 
be the same as captonis, 
TABANUS OKLAHOMENSIS Stone 
(Fig. 67, B) 
Tabanus oklahomensis Stone, Ent. Soc. Wash. Proc. 35: 76-77, 19338. 
Rather small, stout; brownish black; frons very broad; basal callus trans- 
verse; subeallus shiny black; palpus stout, white. 
Female.—Length 18-15 mm. Eye with short, dense, white pile, dark purple, 
with four green-blue diagonal stripes not touching eye margin laterally and 
the lower three curved upward at outer end; eye transverse and short dorso- 
ventrally, the angle formed by lower margin of eyes wider than usual. Frons 
very broad, sometimes less than twice as high as wide and never more than 
two and one-half times the width, the sides nearly or quite parallel; pollen 
of frons yellowish brown, paler between median and basal calli; hair down- 
ward pointing, black except just above basal callus, where it is creamy white; 
vertex somewhat concave, with a shiny-black triangle, in the middle of which 
lies a Sharply defined, raised, dark-reddish ocellar tubercle; a slender black 
line from ocellar tubercle to basal callus; on each side of this line, on middle 
of frons, a large black spot, either separated from the line or broadly joined to 
it; basal callus black, wrinkled, transverse, somewhat protuberant, tapering 
somewhat to each side but touching eyes; line between basal callus and subeallus 
distinctly curved downward medianly ; subeallus swollen and shiny black, with a 
median depressed line; semicircles above antennal bases with pale-yellow pollen. 
