39 1 
(3) Genus Silvius. —Second antennal segment 
very much, shorter than first. Wings without any spots. 
Third antennal segment five rings as in Chrysops. 
Species about twenty-six. 
2. Tabaninae 
The two most numerous genera are Tabanus and 
Haematapota. 
(< a ) Front much longer than broad. Frontal 
tubercle when present not transverse. 
(1) Genus c Iabanus. —Proboscis short and thick; 
vertical in the female, oblique in the male. Antennae 
scarcely longer than head. Third segment five rings. 
First ring is characteristically notched in shape of a 
crescent with a basal process ( Vide Fig. 121). Eyes 
bare. Large flies with humming flight. Species about 
a thousand. 
{b) Front as broad as it is long or broader. Frontal 
tubercle transverse, about four times as broad as long. 
(2) Genus Haematapota .-—-Terminal segment of 
antennae not crescentic. Third segment has four rings. 
Wings adjacent like the side of a roof. They have 
transparent markings. No ocelli. Flight silent. About 
fifty species. 
