234 Heview of " Outlines of the 



The foHowingis an account of the grouping of the organic 

 rennains into distinct assemblages, in the various formations. 



" They are not irregularly dispersed throughout the 

 whole series of these formations, but disposed as it were in 

 families, each formation containing an association of species 

 peculiar in many instances to itself, widely differing from 

 those of other formations, and accompaning it throughout 

 its whole course ; so that at two distinct points on the 

 line of the same formation, we are sure of meeting the 

 same general assemblage of fossil remains. It will serve to 

 exemplify the laws which have been stated, if the oi)server's 

 attention is directed to two of the most prominent forma- 

 tions of this island ; namely, the chalk, and the limestone 

 which underlies the coal in JNorthumberland, Derbysnire, 

 South Wales, and Somerset. Now, if he examines a col- 

 lection of fossils from the chalk of Flamborough head or 

 from that of Dover cliffs, or, it may be added, from Po- 

 land or Paris, he will find 8 or 9 species out of 10 the same; 

 he will observe the same echinites associated with the same 

 shells ; nearly half these echinites he will perceive belong 

 to divisions of that family unknown in a recent state, and 

 indeed in any other fossil bed except the chalk. If he next 

 proceeds to inspect parcels of fossils from the carbonifer- 

 ous limestone, from whichever of the above localities they 

 may have been brought, he will find them to agree in the 

 same manner with each other ; that is, he will find the same 

 corals, the same encrinites, the same productae, terebratu- 

 lae, spiriferae, &c. ; but if he lastly compares the collec- 

 tion from the chalk with that from the mountain lime, he 

 will not find one single instance of specific agreement, and 

 in very few instances any thing that would even deceive an 

 unpractised eye by the superficial resemblance of such an 

 agreement." p. 10. Introd. 



Concerning those genera and species of fossils that have 

 not been discovered in a living state, we have the follow- 

 ing lucid remarks. 



"In speaking of the difference between recent and fossil 

 species, it becomes us to be cautious in pronouncing that 

 the latter do not at present exist because we are not ac- 

 quainted with them in a recent state, and this caution is 

 still more necessarv with regard to those genera which the 

 "dark unfathom'd caves of ocean" may possiblv conceal in 



