13. 
17. 
18. 
19. 
TABANIDA OF OHIO, aa 
Body altogether black; femora of all the legs dark brown 
or black plangens. 
Body usually distinctly marked with yellow; femora yellow 
except sometimes at base 14. 
Face black with a median stripe of yellow pollen frigidus. 
Face yellowish in the middle 15. 
Apical-spot large, reaching beyond the second submarginal 
cell, and invading the first posterior 16. 
Apical-spot does not reach beyond the second submarginal 
cell 18. 
The hyaline space between the cross—band and the apical-spot 
is confined to a small triangle in the second and third 
posterior cells moechus. 
The hyaline triangle reaches across the first posterior cell Wee 
Abdomen with a broad yellow ‘longitudinal stripe in the 
middle enclosed between two black stripes univittatus. 
Abdomen uniformly black or black with three dull yellow 
stripes 4 lugens. 
Abdomen yellow with four black stripes ep 
Abdomen black, yellow on the sides, and with yellow tri- 
angles on the segments indus. 
Frontal callosity and scutellum yellowish vittatus. 
Frontal callosity black; scutellum at base more or less 
blackish striatus. 
Key to the Males. 
Apex of the wing beyond the cross—band is hyaline 
Apical-spot present : 
Face yellow in the middle niger. 
H= bo 
Face wholly black 3} 
Base of fifth posterior cell with a hyaline spot; anal cell nearly 
hyaline carbonarius. 
Base of the fifth posterior cell uniformly brown; anal cell 
infuscated celer. 
Whole body brown 5s 
Body black or at least plainly marked with black 6. 
First segment of antenna swollen; abdomen uniformly brown 
above, with a small triangle on each segment behind the 
first brunneus. 
First segment of antenna not swollen; abdomen above lighter 
at base with a darker design on each segment behind 
the first flavidus. 
Abdomen grayish black, or black with or without a median 
yellow stripe i. 
Abdomen at least yellow on the sides of the first two seg- 
ments; or with a middorsal row of gray triangles 10. 
Abdomen black with a middorsal yellow stripe 8. 
Abdomen uniformly black 9. 
The hyaline triangle produced forward to the costa obsoletus. 
The hyaline triangle not produced beyond the second longi- 
’ tudinal vein lugens. 
Hyaline triangle unusually small, confined to the apices of the 
sécond and third posterior cells moechus. 
Hyaline triangle not unusually small; dark picture of the wing 
rather dim plangens. 
