strata of the earth, or by their casts preserved in the more 

 solid rocks. Of the single genus of shells, called Ammo- 

 nites, for example, upwards of three hundred fossil species 

 have been described; and, of these, a hundred species 

 belong to our own strata ; yet, not a single individual, in a 

 living state, is now found to inhabit the waters of the 

 globe. Almost every stratum, composing the crust of the 

 globe, from the newest alluvial deposits to the oldest tran- 

 sition rocks, abounds with the fossil relics of different 

 classes of the Animal Kingdom, from whose remains, 

 often mutilated, imperfect, or extraordinary in their forms, 

 the Zoologist must learn to decypher the history of the 

 species, and discover their relations to the existing races. 

 A new and boundless field of inquiry is thus laid open 

 to his investigation, in the study of the characters and 

 relations of Fossil Animals a study highly interesting 

 to the Physiologist, as pointing out the successive creation 

 of animal forms, and the changes which organization has 

 experienced since the first appearance of animals upon this 

 earth, and essential to the Geologist, as determining the 

 comparative antiquity and the identity of strata, and 

 unfolding the nature of those terrible events that have 

 repeatedly broken up the surface of this planet, raising 

 the inhabitants of the sea to the summits of lofty moun- 

 tains, and sinking extensive forests with all their animated 

 inhabitants beneath the bed of the ocean. 



The study of the animal kingdom forms an important 

 branch of Natural History, or that science which treats of 

 the properties and relations of all the natural bodies which 

 can be considered as proper objects of human investiga- 

 tion ; and it is intimately connected, not only with all the 

 other branches of that extensive department of knowledge, 

 but likewise with various branches of Medicine, Chemistry, 

 Agriculture, and other sciences and arts. 



The material substances every where surrounding us, 

 and which form the objects of Natural History, are conti- 

 nually acting, directly or indirectly, on our bodily frame, 



