1917] The Wing Venation of the Cercopidce 29 



oval cell that is rather characteristic of the venation of these 

 genera. (Figs. 13, 15, 17, 19.) In Lepyronia (Figs. 5, 15) sub- 

 costa is so closely joined to the radius that a part of the branches 

 of radius appear to belong really to subcosta. In the genus 

 Clastoptera (Figs. 9 atid 21) subcosta is free and runs from the 

 base of the wing ending in the costal border about half way 

 from the base to the apex of the wing. 



Radius is typically three branched in the Cercopidae. These 

 branches represent in my opinion radius one, radius two plus 

 three and radius four plus five. This relationship seems to be 

 perfectly clear in Monecphora (Fig. 1) where radius one branches 

 from the main stem and runs parallel with it for some distance 

 and then turns toward the costal border. In the adult wing 

 (Fig. 11) this basal part is all united in the same vein so that 

 radius one appears as a branch of radius two plus three. In the 

 genera closely related to Aphrophora there is a strong recurved 

 trachea running from radius two plus three to the costal border 

 (Figs. 3, 5, 7), this I believe represents radius one whose attach- 

 ment has simply been shifted further and further distally. 



No nymphs of any of these genera, however, show a typical 

 radius one, i. e., as a branch from the main stem of the radius. 

 The adult wings of these genera also show a strong vein running 

 from radius two plus three to the costal border. 



In the genus Clastoptera (Figs. 9 and 21) there is no evi- 

 dence of a radius one, unless we call certain fine branches which 

 occur near the apical angle of the wing this trachea and con- 

 sider the small dark colored cell at the apical angle, cell radius 

 one. However, it is more likely that this represents radius two. 

 Radius two plus three usually shows some fine lateral branches 

 towards the tip but none of these are very constant and are not 

 worthy of being named. 



The medial trachea in all our genera that I have examined 

 is unbranched. Thus it resembles very closely the condition 

 that has been found in certain genera of the Jassidae. The 

 medial trachea lies very close to the radial trachea but the 

 medial vein is in all of our genera closely connected with cubitus, 

 so closely joined as to appear as a mere branch of cubitus. 



In the three genera Aphrophora (Fig. 3), Lepyronia (Fig. 5) 

 and Philaenus (Fig. 7) cubitus is typically two-branched as it is 

 in many other genera of the Homoptera that I have examined. 



