LEPIDOPTERA. 215 



wing near its base a small lobe (Fig. 243,^'), which extends 

 under the costal margin of the hind wing; while the greater 

 part of the inner margin of the fore wing overlaps the hind 

 wing. This arrangement assures the acting together of the 

 two wings. 



This projecting lobe is named thefugum or yoke ; and the 

 moths possessing this organ are termed the Jugatae or the 

 Jugate Lepidoptera. 



This suborder includes only two families; one represented 

 by minute moths, the other by moths of medium or large 

 size. 



Family HEPIALID^E (He-pi-al'i-dae). 

 The Swifts. 



The members of this family are of medium or large size. 

 Figure 244 represents one of the larger species. Our best 



FIG. ztA.Hepialus argcnteomacvlattu. 



known forms are brown or ashy gray in color, with the wings 

 marked with silvery white spots. 



It is said that these moths fly near the earth, and only in 

 the evening after sunset, hiding under some low plant, or 

 clinging to the stalk of an herb during the day. Some of 

 them fly with extreme rapidity, with an irregular mazy flight, 

 and have, therefore, been named Swifts by collectors. They 

 are attracted to lights. Figure 238 represents the venation 

 of the wings of Hepialus (He-pi'a-lus). 



