120 University of California Publications. [Entomolooy 



of veins, as contrasted with the Mantida\ They also present' 

 in most cases, a modification of the independent region in the 

 form of an enlarged cross vein, or an abrupt branching of the 

 independent veins, which disturbs very strikingly the uni- 

 formity of the wing. The veins are extremely variable, how- 

 ever, so that there can be said to be here a tendency toward a 

 specialization, rather than one already accomplished. 



The Locustidse and Gryllida? have very simple hind wings, 

 but the front wings are distinctly changed for the production 

 of the stridulating organ in the male, and a corresponding 

 though less pronounced change in this structure in the female. 

 In the Locustidffi there has been a great reduction in the num- 



FIG. 57. Diagiamatif representation of the wing of an Acridid. 



l)er of the independents without much decrease in the size of 

 the areas, and there are fewer cross veins, thus making numer- 

 ous larger cells rather than a dense reticulation. In the 

 Gryllida3 the median area is almost entirely suppressed, leaving 

 only a few independents spreading out fan-like. 



The venation throughout these families differs from that in 

 Blattidee, in that the independents of the first group are 

 attached as branches to the primary. They resemble in this 

 respect their Paleozoic ancestors. In the matter of the homolo- 

 gies of the veins, there is no difficulty in comparing these 

 venations with those of Blattida^, so the same questions arise as 

 did in that family. 



HETEROPTERA. , 



The Heteroptera stand in a somewhat intermediate position 

 between the Orthoptera and the Coleoptera. With the former 

 they agree in the leathery texture of the front wings, and with 

 the latter in the close application of the wings to the l)ody 

 when at rest. In neither case is there close similarity, how- 

 ever — notliing to suggest the probability of a genetic relation- 

 ship. It is likely that the order of their specialization was 

 that which the fossil remains thus far known indicate, viz., 



