OF CREATION. 



27 



of bivalve shells belonging to animals of low organiza- 

 tion, and allied to the Terebratula; of a few other 

 shells, both bivalve and univalve ; and, last of all, of 

 a number of the many-chambered shells of a carnivo- 

 rous animal * like the cuttle-fish, a creature of high 

 and complicated organization among the Inverte- 

 brata, and which seems to have been introduced 

 among the very earliest of the species intended to 

 people the primaeval seas. All these animals must 

 have been to a certain extent contemporaneous ; and 

 it is worth while to remark, concerning them, that 

 they exhibit some instances of very imperfect, and 

 some of the most perfect, development of the great 

 kingdom of nature to which they belong. In the 

 older beds, at least until the termination of the first 

 great epoch, the silurian, there seem, indeed, only 

 to have been introduced successive modifications 

 and additional species of the invertebrated type ; and 

 not till its close did the fishes appear, as if preparing 

 the way for the next period, marked by the preva- 

 lence of these more highly organized beings. 



As the animals of the newer differ so little from 

 those of the older portion of the first period, at least 

 in points which admit of general description, I shall 

 not describe them separately ; but, having already of- 

 fered a few remarks on the mineral structure of the 

 rocks, I shall proceed at once to explain in succession 

 those groups which are most interesting and characte- 

 ristic. In this way I hope to communicate something 

 like a distinct notion of the results of geological inves- 

 tigation with regard to the first inhabitants of the 

 earth, and not only show the general fact, that impor- 



* OrthroceratiteS) and several allied forms. 



c 2 



