384- EXTERNAL ANATOMY OF INSECTS. 



affixed to the postpectus a . They include, the Ace- 

 tabulum, Coxa, Trochanter, Femur, Tibia, and 

 Tarsus. 

 a Acetabulum (the Socket). The socket in the Post- 

 pectus in which the leg is planted b . It includes the 

 Pessella. 



A Pessella (the Pessella). Two little acute processes, 

 fixed one in each, in the socket of the hind-legs in 

 male Tettigoniw, which appear designed to keep 

 down the Opercida . 



b Coxa (the Hip). Thejirst joint of the leg which 

 plays in the socket d . 



c Trochanter (the Trochanter). The second joint of 

 the leg, by which the thigh inosculates in the Coxa. 

 It appears to have no motion separate from that of 

 the thigh. It is sometimes biarticulate e . 



d Femur (the Thigh). The third joint of the leg, long 

 and usually compressed f . It includes the Gony- 

 theca. 



A Gonytheca (the Knee-pan). A concavity at the apex 

 of the thigh, underneath, to receive the base of the 

 Tibia ». 



e Tibia (the Shank). The fourth joint of the leg, very 

 long, and usually triquetrous h . It includes the 

 Epicnemis, Molida, Talus, Calcaria, and Coro- 

 nula. 



a Plate XIV. Fig. 5—8. 



b Plate VIII. Fig. 2, 4, 11, 13, &c. o" . « Ibid. Fig. 18. q" . 



A Plate XIV. Fig. G— 8; and XXVII. Fig. 12. p". «= Ibid. q"\ 



f Plate XIV. Fig. 5-8; and XXVII. Fig. 6— 8. /'. 



« Plate XXVII. Fig. 7, 8, 15. ?•'". 



h Plate XIV. Fig. 5—8.*". 



