=I 
TABANUS FROM THE ANGLO-EGYPTIIAN SUDAN, 1 
latter, rather than a distinct species. While this is certainly possible, it seems 
for the present advisable—until the question can be definitely decided by the 
examination of further material belonging to both sexes—to concede specific 
rather than merely varietal rank to T. mordax. Although on a cursory examina- 
tion Tabanus mordax may easily be mistaken for 7’. leucostomus, since, in the 
female sex at any rate, the abdominal markings in the two cases are identical, 
the former may be distinguished from the latter by the great development of the 
supra-antennal protuberance, and by the absence of an appendix to the anterior 
branch of the third longitudinal vein, 
