156 MISC. PUBLICATION 303, U. S. DEPT. OF AGRICULTURE 
Type locality—Red Lake Falls, Minn. 
Distribution—British Columbia to Labrador and Nova Scotia. 
July 18 to August 27 (Baddeck, Cape Breton Island, Nova Scotia). 
TABANUS MELANORHINUS Bigot 
(Fig. 75, B) 
Tabanus melanorhinus Bigot, Mem. Soc. Zool. France 5: 642-643, 1892; Philip, 
Canad. Ent. 68: 155, 1936. 
Rather small; blackish, with three rows of gray spots on abdomen; prescutal 
lobe yellow brown; femora dark; subcallus denuded; eye pilose; palpus stout 
basally. 
Female—Length 11-15 mm. Eye with dense, short pile, purple. with four 
green bands. Frons yellowish gray, three times as high as width at base, 
distinctly widened above; basal callus shiny dark brown to black, subquadrate 
or slightly wider than high, touching eyes, and usually somewhat rounded 
above; median callus black, small, not well defined and usually not joined to 
basal callus; ocellar tubercle small but distinct, usually orange brown; sub- 
callus denuded, concolorous with basal callus. First two antennal segments 
gray, with black hair; third black tinged with orange brown basally; dorsal 
angle distinct, obtuse; dorsal excision moderate; annulate portion shorter 
than basal portion. Clypeus and lower genae white, with white hair, the upper 
genae tinged with yellow, with black hair. Palpus creamy white, the second 
segment stout basally, with mixed black and white hair. 
Mesonotum black, with gray lines in usual pattern, erect black and recumbent 
yellowish-white hair; prescutal lobe yellow brown. Pleura, sternum, and coxae 
gray, with white hair, the mesopleurite somewhat reddish, with black hair. 
Wing hyaline, the costal cell slightly darkened; venation normal or rarely 
a short stump from vein R: Femora gray; rest of legs yellowish brown, the 
tarsi, particularly fore tarsus, and apex of fore tibia darkened; hind tibial 
fringe black. 
Abdomen above grayish black, with a median row of narrow gray triangles 
and sublateral, oblique, yellowish-gray spots, the ground color around them 
frequently yellowish brown; venter nearly uniformly yellowish brown. 
Male.—Eye densely pilose, the upper facets distinctly larger but the line of 
differentiation not marked; frontal triangle protuberant, denuded; second palpal 
segment about twice as long as wide.- Body coloration essentially as in female. 
Described from a specimen in the United States National Museum 
reared at Topaz, Calif., June 20, 1918. 
Type.—aA female, in the British Museum. 
Type locality—Washington. 
Distribution—British Columbia to California and western Mon- 
tana. June 7 (Topaz, Calif.) to August 9 (Laurel, Mont.). In the 
United States National Museum, 26 females, 1 male. 
A specimen compared with the type by Austen and lent to the 
writer by Philip has been studied. This species is very close to opacus 
Coquillett, differing in the denuded subcallus. Both melanorhinus and 
opacus were reared from larvae collected at Topaz, Calif. It is 
barely possible that the two are the same species, but the writer has 
not seen intergradation between the two such as is found in the two 
forms of 7. hirtulus. 
TABANUS MICROCEPHALUS Osten Sacken 
(Fig. 76, A) 
Tabanus microcephalus Osten Sacken, Mem. Boston Soc. Nat. Hist. 2 (pt. 4, 
No. 4): 470471, 1876; Philip, Minn. Agr. Expt. Sta. Tech. Bull. 80: 
111-112, 1981. 
Rather small, but stout; blackish, with three rows of gray triangles on 
abdomen; femora and tibiae nearly uniformly brown; subcallus pollinose; 
third antennal segment slender. 
