74 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



The coxae. — The three coxae of the grasshopper differ somewhat in 

 their positions on the body. The first is the most freely movable ; it 

 projects downward and its base is almost horizontal. The second coxa 

 is directed outward, downward, and posteriorly ; its base lies in an 

 oblique plane between the pleuron and the sternum. The hind coxa is 

 directed posteriorly ; its basal aperture is on the inner face and lies in 

 an approximately vertical, longitudinal plane. 



cxs 



PIS' 



' A "^^ 



^"^ bcs f n Tr 

 Mer ^ piR 



Tr 95Ap-^ 



Fig. 41. — Structure of the coxae of Dissosfeira. 



A, first coxa and base of telopodite, left, anterior surface. B, base of middle 

 leg, left, anterior surface. C, hind coxa and trochanter, left, anterior (outer) 

 surface. D, articulation of middle coxa to pleural process, right, inner view. 



95AP, apodeme of second abductor of middle coxa; Be, basicosta of coxa; 

 bcs, basicostal suture ; c, pleural articulation of coxa ; Cx?,, hind coxa ; cxs, coxal 

 suture ; Eprn, epimeron ; Eps, episternum ; /, anterior coxo-trochanteral articu- 

 lation ; Mer, meron ; PIS, pleural suture ; Tn, trochantin ; Tr, trochanter. 



Each coxa presents a well-marked basal rim, or hasicoxite, set off 

 by a submarginal basicostal suture (fig. 41 A, B, bcs) which forms 

 internally a strong basicosta (D, Be). Laterally the costa of the mid- 

 dle coxa (fig. 37 B) and of the hind coxa (fig. 38 D, F) are enlarged 

 into wide, shelf-like plates for the accommodation of muscle attach- 

 ments. The basicoxite is very narrow or obsolete on the mesal surface 

 of the coxa, but on the lateral surface it forms a distinct prearticular 

 and a postarticular lobe, the latter being known as the meron (fig. 41 B, 

 Mer). The basicoxal lobes are well developed on the hind coxa (C) 



