Jassidd' of Illinois. IH 



thick, and strong joint; (4) a slender, somewhat prismatic, 

 and more or less spiny tibia; and (5) a three-jointed tarsus 

 terminated by a pair of thick slightly curved claws. 



The anterior wings, or elytra, are long, rather slender 

 organs, quite hard in texture, forming a shield to the deli- 

 cate true wings. The inner basal triangular portion, called 

 the clavum or claval area, is separated from the rest of the 

 wings by a bend or suture known as the claval suture. The 

 venation of the anterior wings is of considerable value for 

 classification. The veins arising from the base have been 

 called sectors. The one on the margin is called the marginal 

 vein. Transverse veins are those appearing towards the tip, and 

 connecting sectors or their branches. The areas between the 

 veins are known as basal and apical cells, and when more than 

 one series exists beyond the basal cells, the additional ones are 

 called the anteapical cells. The veins in the clavum are the 

 claval veins. The hind wings have about six sectors, variously 

 forked and united by a few cross-veins, and afford some of the 

 best and most tangible generic characters. The marginal vein 

 does not lie on the margin but parallel with it. It does not ex- 

 tend all around the wings, therefore some of the posterior basal 

 cells are open. 



Abdomen. The abdomen consists of five segments in the 

 male and six in the female. They taper gradually towards the 

 tip, where are the large genital organs. Figs. 7-9, Plate L, 

 show the structure of the abdominal plates around the ovipositor. 



classifications". 



The classification of the Jassidte has undergone the usual 

 amount of change and confusion and is still not satisfactorily 

 settled; but most authorities agree in placing these insects in a 

 series of quite well-defined groups. Primarily they arrange 

 themselves naturally into two large groups or subfamilies. 

 These subfamilies are characterized by the position of the 

 ocelli. Not that these characters are necessarily of such fun- 

 damental importance that we may establish such high groups 

 upon them, but because they seem correlated with other char- 

 acters harder to express but none the less evident and essential. 

 We will therefore divide this family as follows: 



