THE WINGS OF ITHONID.^ 



175 



is not constant; it sometimes varies in the wings of the two sides of the 

 same individual. 



The wings of the Mantispida; resemble in some respects those of 

 Raphidia; the outlines of the wings are similar ; and the two resemble each 

 other and differ from other neuropterous wings in the transverse bracing 

 of the basal part of the fore wing in each by striking modifications of the 

 courses of principal veins, although this result is brought about in very 

 different ways in the two families. 



The wings of the Mantispidas are much more highly specialized than 

 are those of the Raphidiidse ; the discussion of them has been taken up at 

 this point merely because there seems to be no better place in the series to 

 include it. 



In the Mantispid^ the pectinate condition of the radial sector is very 

 perfect, as is also the development of a gradate series of cross-veins, and a 

 comparatively regular margin of accessor}' veins. 



(/) THE WINGS OF THE ITHONID^ 



Newman in 1853 established the family Ithonesidae for the reception of 

 his genus Ithone (Zoologist, vol XI, Appendix p. CCII). Recently 



isTA 

 Fig. 170. — Wings of Ithone fusca. 



Tillyard ('16) reestablished the family under the name of Ithonidas. As 

 the name proposed by Tillyard conforms to the modern rules of nomencla- 

 ture it is adopted here. 



