134 MISC. PUBLICATION 305, U. S. DEPT. OF AGRICULTURE 
Female.—Length 12-15 mm. Eye with short pile, blue green, with three nar- 
row brownish-purple bands. Frons gray tinged with yellow, with black hair, 
about four times as high as width at base, distinctly widened above; frontal 
callus dark brown to black, subquadrate, touching eyes; median callus black, 
spindle shaped, usually joined by a slender line to both basal callus and ocellar 
tubercle; ocellar tubercle prominent, reddish brown; subcallus concolorous 
with frons. Antenna black, the extreme base of third segment sometimes tinged 
with reddish; first two segments with black hair, the second with a distinct 
dorsal process; third with a low, obtuse, dorsal angle and very slight excision; 
annulate portion slightly shorter than basal portion. Clypeus and genae gray, 
with yellowish-white hair below and some black hair at upper angle of genae. 
Palpus yellowish brown, with concolorous and some black hair, the second 
segment distinctly swollen basally. 
Mesonotum black, with erect black hair, some recumbent yellowish hair, and 
narrow grayish stripes in usual pattern; prescutal lobe reddish brown. Pleura, 
sternum, and coxae dark gray, with a mixture of black and yellowish-white 
hair. Wing hyaline, the costal cell, margin of some of the veins, and furcation 
faintly brown; cell R; slightly narrowed apically and usually a stump at base 
of vein Rz Femora black; tibiae dull orange brown except for black apical 
third of fore tibia; hind tibial fringe black; tarsi black to dark orange brown, 
the fore tarsus darkest. 
FIGURE 64.—Antenna, front view of head, and palpus of (A) Tabanus sonomensis and 
(B) T. daecket. 
Abdomen above black, with orange laterally on tergites 1-4, most extensive 
on tergites 2-8; median black stripe with faint grayish triangles and each 
tergite with a narrow gray band on hind margin; venter orange brown, with 
black medianly, sometimes on lateral margins, and apically; hair of venter 
predominantly pale yellowish, often with some erect black hair medianly and 
apically. ; 
Male—EHye with dense, long pile, the areas of large and small facets not 
greatly differentiated. Second palpal segment stout, with black hair. Hair 
of genae black. Claws of fore tarsi subequal. Thorax somewhat darker than 
in female, the rest of coloration essentially the same. 
Type.—tLectotype labelled and herein designated, one of four co- 
types in the Museum of Comparative Zoology, No. 14520, from 
Sonoma County, Calif., April 27-May 9. Five other cotypes in the 
same cotype series bear other data. 
Type locality —Sonoma County, Calif. 
Distribution—Southern Alaska and Alberta to central California 
and Colorado. April 27 (Sonoma County, Calif.) to October 6 
(Layton, Utah). In the United States National Museum, 145 
females, 3 males. 
TABANUS SONOMENSIS variety PHAENOPS Osten Sacken 
Tabanus phaenops Osten Sacken, U. 8S. Geol. and Geogr. Survey Terr. Bull. 
3: 217, 1877; Hine, Ohio Nat. 5: 241, 1904; McDunnough, Canad. Ent. 
53: 143, 1921; Webb and Wells, U. S. Dept. Agr. Dept. Bull. 1218: 20-26, 
1924; Cameron, Bull. Ent. Research 17: 33-34, 1926; Rowe and Knowlton 
(not Osten Sacken), Canad. Ent. 67: 248, 1935. 
Therioplectes phaenops Townsend, Calif. Acad. Sci. Proc. (2) 4: 597, 1895. 
? Therioplectes maculifer Bigot, Mem. Soc. Zool. France 5: 641, 1892. 
Female-——Somewhat darker than the typical sonomensis, the prescutal lobe 
and palpus often, but not always, black. Frons slightly narrower. Hair of 
lower genae often black, Thorax darker, subshiny, with no pale hair. Furca- 
