90 



cies which they contain, he will undoubtedly have established a limit of error to 

 that amount in the application of the new principle. 



It may, perhaps, be urged that, in the present instance, no serious error could 

 have arisen from the application of the new principle, because fifteen per cent, 

 forms the maximum of variation ; there being every intermediate degree from one 

 to that number. This consideration, however, does not at all modify the bearing 

 of Mr. Conrad's statement, with reference to the per centage test ; because 

 those localities which have furnished the intermediate proportions, and so connect- 

 ed the whole together, might have been destroyed by denudation, or might not 

 have been accessible. Had this (which is by no means an unreasonable surmise) 

 been the case, part of what Mr. Conrad now considers older pliocene would, 

 under those circumstances, have been miocene. 



We are rather surprised that Mr. Taylor should not have directed his atten- 

 tion to the tertiary formations in America. The Transactions of the Geological 

 Society of London, and the pages of the Philosophical Magazine, bear ample 

 proofs of the interest which he felt in those of England. It is true that, at Phila- 

 delphia, he is not exactly in the tertiary district ; but fifty or a hundred miles are 

 nothing in America, and even the crag at Bramerton, the favourite resort of 

 cabinet collectors, will not bear competition with the bank of the Potomac. 



We must not draw our observations to a close, without adverting to the valu- 

 able paper, by Dr. Harlan, on the remains of the Basilosaurus. As the descrip- 

 tion of this animal is before the public in another form,* we shall only allude to 

 its prodigious length, which far exceeds that of any other saurian. 



" We understand from Mr. Conrad, that he was informed by Mr. Creagh, 

 that on his first settlement in that portion of the country, a train of vertebrse 

 belonging to this animal was observed on the surface of this rock extending in a 

 line much over 100 feet in length. This statement agrees with that made by 

 Judge Bree ; 150 feet in length being attributed by him to the Arkansa skeleton." 

 —p. 350. 



Had the Basilosaurus been discovered anywhere but in America, we should 

 have thought the above statement exaggerated ; but we are already familiar with 

 the history of the great Sea Serpent, to which reptile we should, a priori, imagine 

 it to be allied. 



We wonder what Mr. Hawkins, of saurian notoriety would say to this monster 

 of the "pre-Adamite epoch." He compares some of his specimens to Moloch, 

 Satan, and Abaddon ;f but they surely must yield the palm now. 



One more extract and we have done ; it is from the Miscellaneous Intelli- 

 gence : — 



* Dr. H. has published this paper, with many others, in a separate volume Ed. 



-f- Memoirs of Ichthyosauri and Plesiosauri, by Thomas Hawkins, F.G.S., &c, &c, &c. 



