280 THE WINGS OF J A SSI DM 



branched in the wings of many nymphs. This is weh shown in his figure 

 of the wing of a nymph of Ceresa diceros. This interpretation of the 

 identity of cubitus makes the position of the anal furrow, namely along the 

 first anal vein, in the membracid wing agree with that found in those other 

 families of the Homoptera in which an anal furrow is developed. 



The anal veins. — In most members of this family the three anal veins are 

 presented more or less distinct in both fore and hind wings. In the wings 

 of many nymphs the third anal trachea is branched (Fig. 277) ; but in the 

 wings of the adults the third anal vein is simple. 



The tip of the first anal vein usually coalesces with cubitus, thus forming 

 a part of the "marginal veins." (Fig. 279). In the fore wings of the 

 larger number of the genera the second and third anal veins are separate at 

 the base of the wing but coalesce throughout the greater part of their 

 length (Fig. 279); but in the hind wings they frequently coalesce at the 

 base and end separately (Fig. 281). 



The cross-veins. — Funkhouser states that "Of the cross- veins which 

 appear in the fore wing, three only are constant and characteristic of the 

 family, the others being peculiar to certain genera and species and of little 

 comparative importance." These three cross- veins are shown in Figure 

 279; they are the sectoral (5), the medio-cubital (m-cu), and the posterior 

 arculus (pa). 



This last cross-vein is usually in the basal third of the wing but is 

 surprisingly variable in position sometimes migrating beyond the middle 

 of the wing. Funkhouser makes no suggestion as to its identity; to me it 

 seems probable that it is the posterior arculus moved out of its typical 

 position. I am led to this conclusion by a comparison of the membracid 

 wings with that of the cicada in which the arculus is typical. 



The marginal vein. — A very characteristic feature of most membracid 

 wings, and of the wings of cicadas also, is the presence of an undulating 

 vein parallel with the outer margin of the wing. This vein is formed by the 

 united tips of the longitudinal veins, and is termed the marginal vein, as it 

 forms the edge of the veined part of the wing. 



(d) THE WINGS OF THE JASSID.« 



An extended study of the wing-venation of the Jassidaj has been made 

 by Metcalf ('13), who figures in his published account the tracheation of 

 the wings of nymphs of representatives of twenty genera and also the wings 

 of adults of a larger niimber of genera. These represent all of the sub- 

 families and tribes of the Jassidce commonly found in Eastern North 

 America. I reproduce here one of his plates illustrating the tracheation of 

 the wings of nymphs (Fig. 284). The results of this investigation are 

 brieflv as follows: 



