228 
The Ohio Naturalist. 
[Vol. XIV, No. 3, 
narrowed towards the antennae. The width and form of the front 
and the modest brown and gray colors overlaid with a thin coating 
of gray pollen are characters which easily separate longus from 
the other two species considered in this paper. 
1. Female. This form is considered as corresponding to 
the typical specimens described by Osten Sacken. Front widest 
at vertex, gradually narrow toward antennae, frontal callosity 
pale brown, sometimes darker or even nearly black, higher than 
wide, with an unconnected spot above, antenna largely yellowish, 
first two segments clothed with short black hairs, third segment 
long and narrow with a distinct angle near the base on the dorsal 
side, annulate portion clear black, cheeks and lower part of the 
face with silky white hair, palpi white with white and black hairs 
intermixed. Thorax brown with more or less obscured stripes 
and gray pollen, wings hyaline, legs largely brown, apex of front 
tibia, whole front tarsus and apical part of each middle and hind 
tarsus darkened. Abdomen brown sometimes rather dark, 
middorsal stripe gray, very narrow, usually abbreviated poster¬ 
iorly; lateral rows of spots gray, each spot small and usually not 
reaching either margin of its segment. Length 13-16 mm. Speci¬ 
mens from northern Ohio and Eastern Kansas. 
Male. Very much like the female in color. Markings of the 
abdomen quite distinct. Large and small facets of the eyes 
plainly differentiated. Length 13-14 mm. Specimens from the 
same localities as the female. 
2. Female. Smaller and of a clearer brown than number 1. 
Annulate portion of the third segment of the antenna usually 
brown and not black. In some specimens the middorsal stripe 
is visible for nearly the entire length of the abdomen and the 
lateral spots are distinctly larger. Altho structural characters 
are quite uniform thruout this form and the next appear quite 
different from typical longus. I have noted that in many species 
of Tabanus, southern examples are likely to be smaller and of a 
clearer brown than northern specimens of the same species. 
Length 11-14 mm. Specimens from North Carolina and Kansas. 
3. Female. This form appears decidedly small but measure¬ 
ment of length hardly indicates it because of the slenderness of 
the specimens. Coloration and appearance are suggestive of 
form number 2. The atennae are yellowish to the tip. Length 
10-13 mm. Specimens from southwestern Georgia. 
