Dec., 1906.] North American Species of Tabanus. 
25 
black, first segment a little larger than the same in costalis, third 
segment not especially wide, a well defined basal prominence, 
annulate portion about the same length as the basal; legs mostly 
reddish; anterior femur on the upper side, anterior tibia at apex 
and all the tarsi dark; wing hyaline with a small brown stigma; 
abdomen brown, in some specimens notably darker than in 
others, with three yellow, middorsal stripe reaching the apex, 
the lateral ones abbreviated behind. 
Female: Length 12-15 mm., front rather wide, slightly 
narrowed below, clothed with yellowish-brown pollen and a few 
hairs; callosity pale brown, nearly square with a very slender 
connected line above; thorax above rather dark, clothed with 
gray pollen and dark hair, face and sides of thorax with white 
hair. 
Male: Length 12-15 mm., head with an extensive area of 
large facets, small facets behind the large ones compose a band 
entirely behind the point where the eyes unite at vertex; thorax 
a little lighter than in the feamle and clothed with longer hair. 
The eyes in this species are plainly pilose in the female as well 
as in the male and by this it may be known from others. The 
very pale frontal callosity in the female is also distinctive. Many 
specimens taken at San Jose, Guatemala, February 5, 1905. 
They were taken by beating a large grass that grew onlv a few 
yards back from the beech. 
Tabanus lineola Fabricius. This common species is known 
from all the others mentioned in this paper by the oblique, 
angular and connected row of spots on each side of the abdomen. 
It is the only one of these species that has any suggestion of 
stripes on the thorax. Length about 14 mm. 
Tabanus modestus Wiedemann. Length 13-15 mm., general 
color black; antenna red, first segment enlarged with black hairs 
above, third segment with a prominent basal process, annulate 
portion darker in color than the basal; front of normal width, 
slightly narrowed below, clothed with yellow pollen, callosity 
shining black narrower than the front and with a connected line 
above; thorax above grayish-black; wing uniformly dilute 
brownish with a darker stigma; legs black except the base of each 
anterior tibia which is white, and all the other tibiae which are 
reddish except extreme apexes; abdomen with a middorsal nar¬ 
row white stripe, and a more or less obscured stripe of the same 
color on each side only reaching the third segment. 
Specimens are at hand from San Carlos, Costa Rica. The 
size in conjunction with the color of wings and bodv serve to 
distinguish this from other species here mentioned. 
Tabanus nigrovittatus Macquart. General color similar to 
costalis; antenna reddish, first segment slender; third segment 
with an angle above, annulate portion black, slightlv longer 
