294 



^A^ INTRODUCTION TO ENTOMOLOGY 



Sympherobius. — In this genus there are two series of gradate veins 

 in the fore wings; the outer series consists of four cross-veins (Fig. 332). 

 Seven American species have been described. The wing-expanse of 

 these insects ranges from 9 mm. to 12 mm. 



Fig. 332. — Wings of Sympherobius amiculus. 



Psectra. — In this genus there is only one series of gradate veins 

 in the fore wings. The only species is Psectra diptera. The specific 

 name of this species was suggested by the fact that in the female the 

 hind wings are atrophied. This is a widely distributed species both 

 in this country and in Europe. Its wing expanse is from 5 mm. to 

 6 mm. 



Family HEMEROBIID^ 



The Hemerohiids 



The Hemerobiidas include insects of moderate size; in most of 

 our species the wing-expanse is between 12 mm. and 22 mm.; in 

 one species of Megalomns it is only 6 mm. In most of the species the 

 body is brown or blackish and is often marked with yellow ; in some 



