DIPTERA. 



455 



Fig. 540. — Tabanus at- 

 ralus. 



Fig. 541.— 



( h ryso/>s 

 niger. 



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 CJirysops 

 (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^ (Strat-i-o-my-i'i-dse). 



The Soldier-flics. 



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 

 flattened (Fig. 542), and the 

 wings when at rest lie parallel 

 upon each other over the ab- 

 domen. But in some genera 

 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. 542. 



St rat io- 



myia. 



Fig 543. 



FiG. 544. 



