Introduction to the Sj/nopsis of the Acrididce. 2G1 



toward a longitudinal middle furrow, giving the entire disk a pinnate 

 appearance; hence these minute ridges are sometimes alluded to as 

 the pinnce of the femur. The disk is bounded above and below by a 

 -mall but usually distinct carina.- Along the middle of the upper edge 

 runs another keel, to which the name xipper or superior carina is fre- 

 quently applied. This is sometimes simply a raised line or angle ; 

 but in other cases, especially in some genera of the group Q^dipodini, it 

 is quite prominent. The inferior edge is generally channeled for the 

 reception of the tibia vhen folded up. The outer margin of this chan- 

 nel or sulcus is the loiver or inferior carina, and generally corresponds in 

 prominence with the upper one. The femur aftbrds some useful char- 

 acters in describing species, by its length, as compared with that of the 

 abdomen ; by its size, whether comparatively slender or broad, by the 

 greater or less prominence of its carina, etc. 



The method by which the tibia is articulated with thd. femur, ad- 

 mirably adapts it for leaping. The apex of the femur is suddenly 

 expanded vertically, but deeply channeled, leaving a plate on each 

 side, between which the base of the tibia is inserted. This has here 

 two sl;ort, right-angular bends, the articulation being at the sides of 

 the first angle with the lateral plates of the femur ; thus leaving a 

 short lever extending upward, to which the strong extensor muscle, is 

 attached. The flexor muscle is attached beneath in the second angle, 

 which, enables the insect to draw the tibia upward into the channel of 

 the femtir. 



• The posterior tibiiB are furnished at the apex with about four strong 

 spines, pointing downward, to give secure footing in leaping. The 

 posterior face is furnished for about two thirds of its length from the 

 apex with two rows of spines, one row on eachmargin. 



The organ.s of flight consist of two upper wings, elytra, and two 

 under wings, to which the name ivings (alee) is usually applied. 



The elytra are generally in the form of an elongate oval, or an eh n- 

 irate parallelogram, narrowed at the base and rounded at the apex. 

 In the perfect insect they usually reach to, or extend beyond, the tip 

 of the abdomen ; but there are numerous exceptions to this rule in 

 many species, being much shorter than the abdomen, and in a few 

 wholly wanting. When the elytra are absent, the wings are also 

 absent. When folded and at rest, a portion lies horizontally upon the 

 Ijack, the remainder, and much the larger portion, being deflexed 

 vertically against the sides of the abdomen. The upper edge, whicli 

 forms the margin of the suture along the back when they are closed, 

 is usually termed the posterior or anal margin, by most authors, as 

 thev consider them spread; but 1 usually employ the word "upper," 



