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