HORSEFLIES OF THE SUBFAMILY TABANINAE 161 
present; eye pilose; frons rather broad and distinctly widened above; palpus 
stout. 
Female.—Length 12-15 mm. Hye with dense, short pile, purple, with four 
green bands. Frons gray tinged with yellow, about three times as high as width 
at base, distinctly widened above; basal callus shiny chestnut brown to black, 
convex, subquadrate, touching eyes, rounded above; median callus black, rather 
small, separated from, or narrowly joined to, basal callus: ocellar tubercle 
reddish brown, often not clearly defined. Subcallus and upper genae concolorous 
with frons. First two antennal segments yellow brown, with gray pollen and 
black hair; third black, with more or less orange basally; dorsal angle and 
excision moderate. Clypeus and lower genae white, with white hair. Palpus 
creamy white, with white and some scattered black hair; second segment stout 
basally. 
Mesonotum blackish, with five gray lines in usual pattern; prescutal lobe 
yellow brown. Pleura, sternum, and coxae gray, with mostly white hair. 
Wing hyaline, the venation normal. Femora dark, with gray pollen; tibiae 
yellow brown, the apical half of the fore tibia darkened ; hind tibial fringe black 3 
tarsi orange to dark brown, the fore tarsus darkest. 
Abdomen above blackish, with considerable yellow brown laterally; a median 
row of narrow, contiguous, yellow-gray triangles and oblique, sublateral, yellow- 
ish spots, the latter narrow anteriorly, touching hind margins of tergites 2 and 
3, at least, and with inner margins slightly concave; venter predominantly 
yellowish brown. 
Male.—EKye with dense, long pile, the large and small facets rather distinctly 
differentiated; frontal triangle with thin gray pollen; second palpal segment 
creamy white, less than twice as long as thick, with blunt apex. Coloration 
essentially as in female. 
Type.—The female of a pair of cotypes, United States National 
Museum No. 7319, herein designated as lectotype. 
Type locality—Ormsby County, Nev. 
Distribution.—Alberta to northern California and Colorado. 
June 5 (Salt Lake County, Utah) to July 25 (Trout Creek, Utah). 
In the United States National Museum, 19 females, 3 males. 
TABANUS FRONTALIS Walker 
(Fig. 79, 4) 
Tabanus frontalis Walker, List of the Specimens of Dipterous Insects in the 
Collection of the British Museum, pt. 1, pp. 172-173, 1848. 
Tabanus incisus Walker, Insecta Saundersiana, Diptera, v. 1, pp. 26-27, 1850. 
(New synonymy.) 
Medium sized; thorax grayish; abdominal pattern usualiy consisting of a 
broad, dark, median stripe bearing grayish triangles and yellowish-brown 
sublateral spots; wing hyaline; prescutal lobe at least tinged with yellow 
orange; subcallus pollinose. 
Female.—Length 13-16 mm. Eye sparsely but distinctly pilose. Frons yel- 
lowish gray; basal callus shiny brown to black, square or slightly wider than 
high, usually rounded above and touching eyes, and usually connected to the 
slender, black, median callus; ocellar tubercle distinct, orange brown; subeallus, 
clypeus, and genae gray, the former tinged with yellow. First two antennal 
segments orange, the third black except at extreme base; dorsal angle of third 
not prominent and excision scarcely evident; annulate portion shorter than 
basal portion. Palpus pale yellowish, with scattered black hair, the first seg- 
ment entirely white haired; second moderately stout at base. 
Mesonotum black, with gray stripes; prescutal lobe usually orange. Rest of 
thorax and coxae gray, with black and grayish hair. Wing hyaline, the vena- 
tion norma!, rarely a short stump from vein Rs. Legs orange brown, femora 
grayish, and tarsi and apex of fore tibia darkened; hind tibial fringe dark. 
Abdomen above grayish black, with a narrow median row of yellowish-gray 
triangles and a sublateral row of large orange-brown spots, usually contiguous ; 
these spots distinctly grayed and not shiny orange as in many related species; 
the sublateral spot on first tergite not quite touching the anterior margin; 
venter orange brown, darker medianly or entirely grayish black. 
Matle.—Unknown. 
senzie==38—— 1.1. 
