branch: biology of kansas membracid^. 79 



XIX), which are separated by a fold (indicated in the draw- 

 ing by a dotted line). The corium is the anterior portion of 

 the tegmen, and, according to Coding, has a costal and three 

 longitudinal veins proceeding from the base. In no case in 

 the Kansas forms does this hold good, there being no more 

 than two longitudinal and the costa, and frequently only one 

 longitudinal, and the costa, proceeding from the base of the 

 corium. Coding names the veins as costa, radia, and two 

 ulnar. In case of Cyrtolobus vau and Campylenchia curvata, 

 this is consistent if the two ulnars are fused at the base, but 

 in the majority of forms there is but one vein other than the 

 costa proceeding from the base of the corium. 



In the study of the nymphal pad some of this fusing and the 

 disappearance of several veins is cleared up. In the nymphal 

 pad there are two veins in the costal region, the costa and 

 subcosta ; these fuse in the adult and are usually referred to 

 as the costa. (See fig. 75, pi. XIX.) 



Frequently, as in Ceresa bubalus, the one longitudinal vein, 

 other than the costa, is branched soon after leaving the base, 

 and forms the radial and one ulnar vein. In the njonph pad 

 is found one other vein "media," which is fused with the radia 

 in the adult. 



The clavus has usually two anal veins, one of which fre- 

 quently forms the posterior margin of the tegmen for some 

 distance; the other anal vein usually joins the marginal vein 

 at about its middle point. Much more discussion of the veins 

 in tegmina of different species could be given, but observations 

 on the drawings of the tegmina will give a conception as to 

 the variation of the venation. 



Cells of the tegmen (and in this instance I take Ceresa buba- 

 lus as a typical illustration, as it appears to be nearly constant) 

 have four basal cells, the third of which is frequently referred 

 to as the sutural area, as it contains the sutural fold between 

 the clavus and corium. (See fig. 75, pi. XIX.) The costal 

 cell in all forms is long and slender, proceeding to the first 

 apical cell without the intervention of a discoidal cell. 



The cells between the apical cells and the basal cells are 

 known as discoidal cells, and usually number three. 



The apical cells are typically five in number, although sonie 

 genera may have only four, as in Micrutalis. These cells are 

 marginal and are surrounded by nervules, no nerves or nervules 



