EXTERNAL ANATOMY OF INSECTS. 661 
Entomologists have denominated—the coxa or hip—the 
trochanter—the femur or thigh—the tzbza or shank—and 
the tarsus or foot. Where the structure and use of the 
fore-leg is different from that of the four hind-legs, I pro- 
pose calling these pieces by names corresponding with 
those which anatomists have appropriated to the arm in 
the higher vertebrate animals: thus, as you will see in 
the table, I call the whole fore-leg the brachium or arm ; 
and the cora becomes the clavicula or collar-bone ; the 
trochanter, the scapula or shoulder-blade ; the femur, the 
humerus or shoulder; the ¢2bia, the cubitus or arm; the 
tarsus, the manus or hand. But let me not lead you to 
suppose that the pieces, either in the arms or legs of in- 
sects, which are there named after certain others in verte- 
brate animals, precisely correspond with them—by no 
means—since that is a, very doubtful point; and some of 
them, as the trochanter, clearly donot. Many gentlemen 
skilled in anatomy, as I have before observed *, have 
thought that what is regarded as the coxa in insects really 
represents the femur : but there are considerable difficul- 
ties in the way of this supposition, several of which I then 
stated. I shall not however enter further into the sub- 
ject, and take the above names—since this application of 
them is so general and so well understood, except with 
regard to the fore-leg, under certain circumstances—as I 
find them. I shall now consider them in the order in 
which I have named them. 
a. Coxa or Clavicula». The coxa is the joit that 
* See above p. 589. Some physiologists have been of opinion, 
that in birds, what is called the thigh should properly be denominated 
the dibia, and that this last is really the tarsus. Illiger, Terminologie, 
184, § 185. n. 1246, » Prares XIV. XV. XXVII. p. 
