X 
PREFACE. 
of the extraordinary opportunities which he possessed, the history of 
these fossils must now be chiefly formed with the materials which he 
has furnished. The full range of the plaster quarries, so rich in 
fossil bones, and the unlimited power of examining the rich cabinets 
of fossils which have been dragged to the National Museum, from 
different parts of France and of the Continent ; and, above all, the 
opportunity of comparing these with the recent bones in the pro- 
digious collections of skeletons, &c. in the Museum, have placed 
before him a rich harvest, which he has most carefully reaped. By 
his persevering assiduity he has accomplished the most important 
discoveries respecting several unknown animals which have existed 
in former ages of this planet. To have omitted an account of these 
discoveries, would have been a departure from the intention of the 
work ; and to have extracted less than is here given, could not have 
been done without injurious mutilation. 
From the frequency with which these invaluable labours are re- 
ferred to, it would have been very difficult to have marked each 
reference ; it has, therefore, been thought preferable to give two 
lists of the references to the places where the several subjects are 
treated of in the original works of these authors. 
It is presumed, that the phenomena noticed in this work may lead 
to highly useful discoveries, and to the establishment of important 
truths. Already the mineralized remains of numerous unknown 
plants and animals have added facts, supplementary, as it were, but 
of a highly interesting nature, to the sciences of Botany and of 
Zoology. From the connected examination of fossils, and of the 
strata which contain them, much useful information may be ex- 
pected to be obtained, respecting the situations in which various 
