393 
The bones of the feet of one kind required to be classed with the 
heads of one of these genera, and the bones of the feet of the other 
kind with the head of the other genus. But how was this separation 
to be effected ? Did the feet with three toes belong to the head with 
tusks, and those with two toes to the heads without tusks, or should 
they be disposed in a contrary combination ? 
After much perplexing investigation, he derived considerable aid by 
meeting with a head without tusks, not larger than that of a hare, 
and fortunately with a didactyle foot of the same proportions. Thus 
assisted, he proceeded in his comparisons, and was at last able to 
determine that the didactyle feet belonged to the Anop lotheriu m , and 
the tridactyle to the Palceotherium. 
M. Cuvier observes, that the first information to be obtained, in the 
examination of the remains of a fossil animal, is with respect to its 
grinding teeth. By these may be ascertained whether the animal 
was carnivorous or herbivorous ; and if the latter, the order of herbi- 
vorous animals to which it belonged, may, even, thereby, be deter- 
mined, to a certain extent. 
A superficial examination soon showed him, that almost all the ani- 
mals found in the plaster-of-paris quarries, round Paris, have the grinders 
of the herbivorous pachydermata ; those of the upper jaw possessing 
a crown formed of two or three simple crescents, succeeding to each 
other ; a configuration which may be seen to exist in the rhinoceros 
and the daman, Hyrax, Linn, two genera of the pachydermata. The 
ruminating animals, indeed, have also grinders composed of two or 
three crescents ; but their crescents are double, and have each four 
lines of enamel ; whilst in the pachydermata they are simple, and have 
only two lines. These remarks were confirmed by the appearances 
yielded, in these fossils, by the upper grinders ; their outer face 
having three projecting ribs, which divide it into two shallow depres- 
sions ; their crowns are square, and have peculiar inequalities. These 
characters serve to remove, decidedly, these fossil animals from 
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VOL. III. 
