TABANIDAS OF OHIO. 55. 
Female: Front with parallel sides, frontal callosity shining brown, 
not quite as wide as the front, nearly square and with a linear prolon- 
gation above. Segments of the abdomen above with prominent gray, 
hind margins which expand into large gray triangles in the middle; 
usually a black mark on the anterior part of each of the second and third 
segments at the apex of the gray triangle. 
Male: The division between the large and small facets of the eye 
prominent; head slightly more convex than in the female but nearly of 
the same size, coloration of the whole body the same as in the female. 
Habitat: Common in all parts of Ohio in August. 
This species is very near exul and abdominalis, neither of 
which have been recoznized from this state, although it it within 
their range. The large, gray, abdominal triangles are characteristic 
of sulcifrons. In abdominalts the first posterior cell is closed, and 
the front in the female is noticeably narrowed. In exul the head 
of the male is sub-hemispherical and the abdominal triangles are 
moderate. Regarding its relationship with variegatus see under 
that species below. 
In certain parts of Ohio this species is so abundant that it is 
one of the worst of stock pests. 
TABANUS SUPERJUMENTARIUS Whitney. 
Length 16-20 mm. This species resembles trimaculatus in many 
respects but the following differences may be noted: the legs are uniformly 
black or at least dark with occasionally a suggestion of reddish at the 
bases of the tibiae; the wings are uniformly subhyaline with no darker 
margins to the cross veins and bifurcation of the third vein; dorsally, 
abdominal segments two, three, four and five each with a very small 
white triangle in connection with the middle of the posterior margin; 
ventrally, there is not the contrast between the colors of the median and 
lateral areas exhibited in trimaculatus. 
The male and female are colored alike except in the specimens before 
me the thorax is not so distinctly white in the former as in the latter. 
Habitat: Akron and Cincinnati. 
TABANUS TRIMACULATUS Palisot de Beauvois. 
Length 16-19 mm. Antennae dark, nearly black, palpi yellowish; 
thorax dorsally with whitish pollinose stripes and brownish intervals, 
scutellum uniformly whitish pollinose; legs black except base of all the 
tibiae which are white; wings hyaline, costal cell brown, bifurcation of 
the third vein, cross veins and sections of veins that have a transverse 
direction margined with brown; abdomen dorsally black with a large 
white triangle in connection with the middle of the posterior margin of 
each of segments three, four and five; abdomen ventrally white on the 
sides and a wide black median stripe. 
The male and female differ only in sexual characteristics. 
Habitat: All sections of the state during the latter part of 
May and the first half of June. Occasionally as late as July first. 
The three prominent triangular white markings of the ab- 
domen easily distinguish this species. 
