176 



THE WINGS OF NEUROPTERA 



The type of the genus Ithone is the species described by Newman under 

 the specific nscvae, fusca; the wings of this insect are figured here (Fig. 170). 



The wings of Ithone fusca bear a superficial resemblance to those of the 

 Corydalinas; but in Ithone the humeral A^ein of the fore wings is recur\^ed 

 and branched and veins Sc and Ri do not coalesce at their tips. 



In this species there is a single radial sector, which is pectinately 

 branched; and most of the branches of this vein are forked at the tip. 

 Media is two-branched in both wings; and vein Cui is very stout. 



rca 



Fig. 171. — Wings Rapisma viridipennis; rca, radial cuneate area. 



This Species is found in Australia and in Tasmania, and has been until 

 recently the only species of the genus Ithone known. 



Tillyard ('16) describes another Australian insect under the name 

 Ithone fulva. But although the general appearance of the wings of this 

 insect, as figured by Tillyard, is similar to that of Ithone, the differences in 

 structure are so great that it is doubtful if the two are congeneric. The 

 most important difference is that in the fore wings of Ithone fulva the first 

 and second branches of the radial sector arise separately from the main 

 stem of radius, the radius having three sectors. In the hind wings veins 

 Sc and Ri coalesce throughout the distal half of their length. 



The limits and distinguishing characteristics of the Ithonidaj must be 

 determined by a study of other characters as well as those presented by the 



