326 W. D. FUNKHOUSER 



XXXIV, 2, 3. These figures are intended to represent the more usual forms 

 as shown in the family as a whole. It would of course be impracticable 

 to endeavor to depict the large number of minor variations occurring 

 thruout the genera, and no one species has been found which could be 

 figured as a perfectly representative type. 



In the same way a ventral view of the entire thorax is shown in Plate 

 XXXIV, 4. When the prothorax is thus attached, the undersurface of the 

 posterior prolongation of the pronotum will, of course, form the background 

 of such a figure. This, to be sure, would vary remarkably in different 

 species, but may be regarded as more or less typical for all subfamilies 

 with the exception of the Centrotinae. 



THE WINGS 



The wings of the Membracidae have been discussed by the writer in 

 a previous paper (Funkhouser, 1913), and need not be discussed in further 

 detail here except to call attention to certain points in connection with 

 their attachment. 



It must be remembered that in the Homoptera the wings are folded 

 against the body with the costal margin downward. This makes an 

 apparent, but not a real, reverse of the normal position in insects. 

 Theoretically the wing of an insect may be considered as in a plane pro- 

 jecting horizontally from the pleural wall of the body, with the costal 

 region extending directly cephalad (Plate xxxiv, 5). Supported in such 

 a position, the anterior part of the articulating surface of the wing is 

 attached to the anterior wing process of the notum and the upper wing 

 process of the episternum, while the posterior surface is attached to the 

 posterior process of the notum and the wing process or the postparapterum 

 of the epimeron. Actually, however, in most orders of insects the plane 

 of the wing is more likely to be tilted upward, the costal region pointing 

 slightly dorso-cephalad and articulating chiefly with the anterior notal 

 process, while the anal region extends ventro-cavidad and finds its chief 

 connection at the pleural wing process between the episternum and the 

 epimeron. 



In the Membracidae, on the other hand, the costal margin of the wing 

 appears on superficial examination to be attached to the ui)per extremity 

 of the episternum — in fact it actually lies in a groove in this sclerite when 

 at rest — while the anal area is clearly folded against the lower margin 



