O04 MISC. PUBLICATION 305, U. S. DEPT. OF AGRICULTURE 
Mesonotum covered with creamy hair over a dark-reddish ground; rest of 
thorax dark brown, with concolorous hair. Wing brownish, paler posteriorly, 
the cross veins and furcation distinctly margined with brown; cell R; distinctly 
narrowed apically. Legs entirely dark, except basal third of fore tibia, which 
is white, with long white hair. Abdomen entirely black. 
Male.—Coloration as in female except that the white of the mesothorax is 
confined to a lateral band and the outer margin of the scutellum, the rest being 
dark reddish brown. Area of large facets of eye extensive and very sharply 
differentiated from area of smail ones. 
Type—A female from Utah herein designated as lectotype, in the 
Museum of Comparative Zoology. One male and four female cotypes 
from Utah and California in the Museum of Comparative Zoology. 
Type locality —Utah. 
Distribution—Western North America from Washington and 
Idaho south to Sonora and western Texas. April (Death Valley, 
Calif.) to October (Bowie, Ariz.). In United States National Mu- 
seum, 79 females, 24 males. 
TABANUS STYGIUS Say 
(Fig. 41) 
Tabanus stygius Say, Jour. Acad. Nat. Sci. Phila. 3: 33, 1823; Wiedemann, 
Aussereuropaische zweiflitigelige Insekten, v. 1, pp. 181-132, 1828; Say, 
Complete Writings, LeConte ed., v. 2, p. 54, 1855; Osten Sacken, Mem. 
Boston Soc. Nat. Hist. 2 (pt. 4, No. 4): 454, 1876; Hart, Ill. State Lab. 
Nat. Hist. Bull. 4: 239-241, 1895; Hine, Ohio State Acad. Sci. Spec. Papers 
5: 54, 1803; U. S. Dept. Agr., Bur. Ent. Tech. Ser. 12: 28-32, 1906; Philip, 
Minn. Agr. Expt. Sta. Tech. Bull. 80: 28-30, 116, 1931; Schwardt, Ark. 
Agr. Expt. Sta. Bull. 382: 4S—50, 1936. 
Ficture 41.—Antenna, front view of head, and palpus of Tabanus stygius. 
Rather large; thorax gray and abdomen black; wing subhyaline, with a 
spot at furcation; fore tibia unicolorous; frons orange brown, moderately 
narrow. 
Female—Length 20-23 mm. Eye bare, dark green, with two purple bands 
and vestige of a third above. Frons orange brown to dark brown, three and 
one-half to four times as high as width at base, with parallel sides; basal 
callus dark reddish brown, nearly as wide as frons, higher than wide, the 
median callus forming a projection above of about equal length or longer; 
vertex slightly grayish; subcallus, clypeus, and genae orange brown; hair of 
clypeus darker brown. Antenna orange red, the base of third segment lighter 
than rest; basal portion of third rather elongate, with a distinct, rectangular, 
dorsal angle; annulate portion about equal in length to width of basal portion 
at dorsal angle. Second palpal segment moderately elongate, dark brown, with 
darker brown, short hair. 
Mesonotum with white hair and pollen through which show the reddish 
ground color and some indication of stripes: rest of thorax brown, with brown 
hair. Wing pale orange brown, paler posteriorly; cross veins and furcation 
margined with brown; cell Rs; somewhat narrowed apically. Legs entirely 
brownish black. Abdomen dark brownish black. 
