AMPHITHERIUM. 3 
inquiry, first in regard to the geological relations of the 
alleged oolitic stratum, and next, as to the true zoological 
affinities of the fossils. 
The first exception to a generalization that has assumed 
the character of a law is always admitted with difficulty, 
and, by a rigid systematist, with reluctance. The geo- 
logical arguments by which M. Prevost endeavoured to 
invalidate the conclusions of Dr. Buckland, as to the re- 
lative position of the Stonesfield slate, were soon and satis- 
factorily rebutted by Dr. Fitton; the antiquity of the 
oolitic masses could not be diminished to correspond with 
the presumed exclusive Mammalian epoch,—the mountain 
refused to move to Mahomet, and the question as to the 
real age of the rock containing the alleged marsupial fossils 
has not since been agitated. The attempts to do away 
with the anomalous exception, by interpreting the cha- 
racters of the fossil Jaws as indications of an extinct species 
of reptile, or other cold-blooded oviparous animal, have 
been more frequent and persevering; and they assumed 
the appearance of so systematic a refutation of the Cuvi- 
erlan view, in the memoirs communicated by M. de Blain- 
ville to the French Academy, in the year 1838, that a close 
and thorough reexamination and comparison of the fossils 
in question seemed to be imperatively called for, in order 
that the validity of the doubts cast upon their Mammalian 
nature might be fully and rigorously tested. 
By a very singular comcidence the fossil ‘ bones of 
contention, from the Stonesfield slate, are all of them 
portions of the lower jaw; whether belonging to individuals 
of different species, or of different genera, or even, as appears 
by examination of new specimens acquired since the publica- 
tion of Professor de Blainville’s and my own memoirs of 
1838, of different orders of Mammalia. 
