INTRODUCTION. 



Fossil shells, being necessarily without brilliance, colours, or 

 beauty, and frequently imperfect, were formerly rejected from 

 collections as destitute of interest; but since it has been observed 

 that these fossils are precious monuments for the study of the 

 revolutions undergone by different points on the surface of the 

 globe, they have become object* of the greatest interest to the 

 Naturalist, (j). 



It appears to have been proved that the shells, testaceous ver- 

 micularia, echini, and different species of polypi which are found 

 so profusely in the fossil state beneath the soil or on its surface, 

 even in the middle of continents and on the highest mountains (2) , 

 are the remains of multitudes of marine animals which lived in 

 these places, and that several of the species are analogous to 

 those now inhabiting the seas (5). For, as the quantity of these 

 remains is enormous, since we know of masses nearly a hundred 

 miles in extent, and as shells of an extreme thinness and fragility 

 are found entire amongst them, we cannot but conclude that 

 their animals have really lived in these parts of the globe, and, 

 consequently, that the sea has formerly been stationary there (*), 



(1) Conchology, when rendered subservient to geognostic investigations , 

 assumes the rank of an useful science, and then becomes a subject of the 

 highest importance. Bulimus trifasciatus, a very common West Indian shell, 

 occurs imbedded in the same limestone which incloses the fossil human ske- 

 leton, lately sent to the British Museum, from the grande terre of Guadaloupe, 

 by Sir A. Cochrane, proving that rock to be of modern date, and contempo- 

 raneous with the existing creation of animals. — LeacJis Zoological Miscel- 

 lany. Yol. i, p. 42. 



(2) According toTJUoa, shells have been found at the height of 14,220 feet 

 above the sea, on a mountain in Peru. 



(3) M. Defrance has discovered at least 500 species of fossil shells in the 

 calcaire grossier at Grignon, the equivalent of the London clay. 



(4) Les terrains les plus bas, les plus unis, excaves jusqua de tres-grandes 

 profondeurs, ne montrent que des couches horizontals de malieres varices, 

 enveloppant prcsquc toulcs d'innombrables produits dc lu mcr. Des couches 



