D1PTERA. 



455 



The larger species, as well as some of moderate size, 

 belong to the genus Tabanus (Ta-ba'nus), of which nearly 

 one hundred American spe- 

 cies are known. One of the 

 most common of these is the 

 Mourning Horse-fly, Tabanus 

 atratus (T. a-tra'tus). This 

 insect is of an uniform black 

 color throughout, except that 

 the body may have a bluish 

 tinge (Fig. 540). 



To the genus Chrysops 

 (Chry'sops) belong the smaller 

 and more common horse-flies with banded wings (Fig. 541). 

 Nearly fifty North American species of this genus have 

 been described. 



Family STRATIOMYIID/E (Strat-i-o-my-i'i-doe). 



The Soldier-flies. 



The soldier-flies are so called on account of the bright- 

 colored stripes, with which some of the species are marked. 



In the more typical mem- 

 bers of this family the abdo- 

 men is broad and greatly 

 *\ I I flattened (Fig. 542), and the 



|f \ wings when at rest lie parallel 



'tf JttL u P n eacn other over the ab- 



vi 99 domen. But in some genera 



V i - the abdomen is narrow and 



considerably elongate. 



The antennae vary greatly 

 in form ; in some genera the third segment is long and con- 

 sists of several quite distinct rings (Fig. 543) ; in others it is 

 short with but few indistinctly-separated rings and with a 

 bristle (Fig. 544), as in the true true short-horned flies. 



The most distinctive characteristic is the peculiar vena 



FIG 543 ' 





