1870.] OWEN—CHINESE FOSSIL MAMMALS. 431 
interval between the postexternal (6) and the postinternal (d) lobes 
is not closed by a ridge descending from the summit of the post- 
external lobe as in Chalicothervwm swalense*; nor does the inner 
side of the antexternal lobe terminate in so ridge-like a way as in 
Ch. sivalense; it is more rounded. ‘The inner side of the postinternal 
lobe (d) is rounded in Ch. sinense, not angular as in Ch. sivalenset. 
The following are admeasurements of the last molar (m 3’) of the 
two species of Chalicotherium. 
Admeasurements of the last Upper Molar. 
C. sinense. | C. sivalense. 
in. lines.| in. lines. 
Fore-and-aft diameter of outer side ...... 1 qk 1 4 
3 55 inner side ...... 1 + 1 04 
Transverse diameter of fore side ......... 1 8 1 6 
5 as near side ......... 1 4 1 oF 
Falconer observes of the molars of Chalicotherum sivalense, ‘ their 
width is greater than their length” (tom. cit. p. 192); but the di- 
rection of these dimensions is not defined. In Chalicotherium sinense, 
as in Ch. sivalense, the diameter from without inwards equals that 
from before backwards. In speaking of the length of a tooth, one 
ordinarily means the extent to which the crown projects from the 
socket; and this is commonly the “ vertical diameter” of the crown. 
In this sense the length of the molars of Chalicotherium is much less 
than their breadth, whether transverse or antero-posterior. But, 
then, this inferiority of length does not differentiate the molars of 
Chalicotherium from those of Anoplotherium. The length of the 
entire tooth in both genera, which includes the implanted part, is 
greater than any other diameter or dimension. The difference in 
the mineral condition of this Chinese cave-tooth and the fossil 
teeth of the same genus from the upper Miocene of France, Germany, 
and India is very striking and suggestive. 
The older Chalicotherian molars, recognized by Kaup and Lartet, 
are truly petrified fossils. Those also from the Siwalik sands are 
in this state; but Falconer remarks that, when clay is the matrix, 
the bones, and, we may presume, the dentine of the teeth, remain 
white, and, except in being deprived more or less completely of 
their animal matter, they have undergone little alteration (tom. cit. 
* This structure is noticed by the careful and minute observer Falconer, as 
follows :—‘‘ The apex of the posterior reentering angle gives off a like trans- 
verse ridge, which sweeps round into the posterior side.” (Paleeontological Me- 
moirs, 8vo, vol. i. p. 192). 
+ The differential structure in Chalicotherium sivalense is noticed as follows, 
in the same useful and instructive summary of his scientific thoughts and 
works :—‘ This is the ‘transverse ridge,’ which is much inclined downwards 
and joins on with the isolated conical cusp (a, a’, a”) in the anterior and inner 
corner of the tooth, a cusp characteristic of Anxoplotherium.” (Falconer, Palzeon- 
tological Memoirs, vol. i. p. 192.) I may, however, remark that the conical cusp 
is equally characteristic of Paloplotherium, and, though of smaller size, of Hip- 
parion, 
