306 



tatarsal bone, and these by several tarsal bones, the distinction is easily* 

 made. 



The os femoris of birds is distinguishable from that of quadrupeds by 

 its external condyle, which instead of having in its back part, a simple 

 convexity for the outer pit of the head of the .tibia, has two projecting 

 lines: the one, which is the real condyle, and which answers to the 

 upper and outer pit of the tibia, and to the inner pit of the fibula, is 

 stronger marked than the other, which is more external, descends less, and 

 rests on the upper edge of the fibula. Thus the external condyle, in birds, 

 is forked, or hollowed out into a canal more or less deep, in its back part. 



The only quadruped, in which any analogous structure is discoverable, 

 is the kanguroo. In this animal there exists a slight depression on the 

 back part of the external condyle of the os femoris; but the great width 

 of the great trochanter, and several other characters, will always prevent 

 the confounding of the os femoris of a bird with that of a kanguroo. 



Reckoning upon the apparent specific characters of different thigh- 

 bones, found in the neighbourhood of Paris, M. Cuvier concludes that 

 they point out the remains of five or six different species of birds existing 

 in these quarries. 



The shoulder-bones of birds are also easily known, by the particular 

 characters of their extremities. The head is always oblong, from right 

 to left, playing in a corresponding groove formed by the scapula and 

 clavicle ; the two lateral ridges widening this part of the bone consider- 

 ably. The lower end is distinguishable by an articular pulley, divided 

 into two parts: one of which, the inner or lower, which is nearly round, 

 is for articulation with the ulna; and the other, the outer or upper, which 

 is oblong in the direction of the bone, and rises a little obliquely on the 

 anterior face of the bone, is for the radius. In quadrupeds, the head is 

 always round and the ridges small ; and in the lower end, the ulnar pul- 

 ley is always concave, and the radial is hollowed into a groove in those 

 in which the fore-arm has no supination. 



nice investigation and comparison, M. Cuvier is supported in his 



