URSUS SPELUS. 97 
Of no other quadruped than the Bear is the femur more 
likely to be mistaken by the unpractised Anatomist for 
that of the human subject, especially the femur of the 
gigantic extinct species commonly found in caves: figures 
of the human thigh-bone (fig. 33) and of that of the 
Ursus speleus (fig. 32), reduced to the same proportions, 
are, therefore, subjoined. 
The bear's femur differs chiefly in its greater thickness 
compared with its length; in being straighter; in the 
much greater vertical extent of the large trochanter 
(a), and the less projection of the small trochanter (4), in 
the less oblique inflection of the neck of the bone, in the 
minor expansion of the distal condyles, and in the smaller 
size of the articular surface for the patella or knee-pan. 
The difference between the femur of the Ursus speleus 
and the femur of the Ursus Arctos and Ursus ferox, is ana- 
logous to that which has been pointed out in the humeri ; 
the femur of the Grisly Bear being broader in proportion to 
its length, especially at its two extremities: it is owing to 
this breadth that the lesser trochanter is thrown wholly to 
the posterior surface of the bone, the inner margin being 
continued beyond it, whilst in the Cave Bear the lesser 
trochanter, though on the posterior surface of the bone, pro- 
jects a little beyond the inner margin. At the distal end 
of the bone the tuberosity above the internal condyle, cor- 
responding with that in the humerus, is larger and more 
prominent in the Grisly than in the Cave Bear: the same 
difference in the position of the lesser trochanter is pre- 
sented by the White Bear as compared with the Cave 
Bear, and the extremities of the bone are relatively 
broader in the White Bear. 
I have determined portions of the fossil leg-bones 
(tibiz and fibula), entire ankle or tarsal bones, and bones 
H 
