4l6 ARTICULATES I INSECTS. 



shaken down by the wind. Here they burrow, remain 

 through the winter in the larva form, pass into the pupa 

 state in early summer, and in a few days afterwards come 

 forth in the winged state. 



The Genus Chione contains the Snow-Gnats, which are 

 very small, wingless, and look like spiders, and are found 

 in great numbers in the last of winter upon the snow. 



The Genus Simulium comprises the Black Flies and 

 their allies. The larvae are aquatic. 



TABANID.E, Leach, OR HORSE-FLY FAMILY. This 

 Family comprises large diptera which in the female have 

 a proboscis enclosing six sharp lancets, and in the male, 

 four ; the eyes are very large and cov- 

 304. er near iy t he w hole head, thorax ob- 



long, and abdomen triangular. They 

 are among the largest of the Diptera, 

 and are notorious for their attacks 

 upon horses and cattle, piercing them 



Horse-Fly, T. hneola, Fabr. r 



and sucking their blood, and causing 

 them great pain. The larvae live in the ground. 



The Genus Tabanus contains the Black Horse-Fly, T. 

 atratus, Fabr., which is seven eighths of an inch long, and 

 expands nearly two inches ; the Orange-belted Horse-Fly, 

 T. cinctus, Fabr. ; and the Lined Horse-Fly, T. lineola, 

 Fabr., at once distinguished by the whitish dorsal line. 

 ASILICI, Latr. y OR ASILUS FAMILY. This Family com- 

 t Fig. 305.^ prises diptera which are of large 



size, with the body long, slender, 

 and clothed with stiff bristles. 

 They are rapacious, seizing and 

 bearing away other insects. The 

 larvae live in the roots of plants. 

 The Genus Asilus contains the 



Asilus, A. aZtuans, Linn. principal SpCClCS. 



A. sericeus, Say, is about an inch long, brownish yellow, 



