EXTERNAL ANATOMY OF INSECTS. 383 
affixed to the postpectus*. 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 >. It includes the 
Pessella. 
A. Pessetxa (the Pessella). Two little acute processes, 
fixed one in each, in the socket of the hind-legs in 
male Cicad@, which appear designed to keep down 
the Opercula °¢. 
b. Coxa (the Hip). The jirst joint of the leg which 
Cc. 
plays in the socket 4. 
TrocHantTEr (the Trochanter). The second sii 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 *. 
d. Femur (the Thigh). The third joint of the leg, long 
and usually compressed *. It includes the Gony- 
theca. 
A, GonyTHEca (the Knee-pan). A concavity at the apex 
e@. 
of the thigh, underneath, to receive the base of the 
Tibia &. 
Tra (the Shank). The fourth joint of the leg, very 
long, and usually triquetrous®. It includes the 
Epicnemis, Molula, Talus, Calcaria, and Coro- 
nula. 
2 Pirate XIV. Fic. 5—8. 
> Prate VIII. Fic. 2, 4, 11, 13, &c. 0”. © [bid. Fic. 18. q'”. 
4 Prare XIV. Fic. 6—8. and XXVII. Fie. 12. p’. © Ibid. q". 
f Prate XIV. Fic. 5—8. and XXVII. Fic. 6—8. r”’. 
® Prate XXVII. Fie. 7, 8, 15. 7”. 
h PratE XIV. Fic, 5—8. 5”. 
