NEUROPTERA 



295 



the body is pale yellow. The wings are usually hyaline or pale 

 yellowish. 



This family has been greatly restricted in recent times ; formerly 

 there were included in it the members of the two preceding and the 

 three following families. 



Fig. 333. — Wings of Hemerobius humuli 



As now restricted this family is composed of a group of genera 

 that are characterized by a distinctive mamier of specialization of the 

 radius of the fore wings. This feature is a coalescence of vein Ri and 

 the stem of the pectinately branched radial sector, which results in 

 what I have termed the suppression of the stem of the radial sector. 



A comparatively simple example of this condition is exhibited 

 by Hemerobius hamuli; in the fore wings of this species (Fig. 333), 

 veins R5, R4, and R2+3 arise separately from what appears to be 

 the main stem of the radius but which is really vein Ri and the basal 

 part of the radial sector coalesced. 



An early stage in the suppression of the stem of the radial sector 

 is shown in the hind wing oi Hemerobius humuli (Fig. 333). Here 



