340 Proceedings of the British Association. 



coast of Essex and Suffolk. Among the mammalia, which the au- 

 thor states really belong to the crag, is the Mastodon angustid ens, 

 of which several teeth have recently been obtained in Norfolk from 

 localities adjoining the parish of Withingham, the spot from which 

 Dr. W. Smith states the specimen to have been procured which is , 

 figured in his " Strata Identified." Mr. Charlesworth conceived 

 the discovery of the remains of the mastodon in this formation, as 

 affording an argument to prove the relative ages of these rocks, as 

 no remains of this animal have been found in America in beds more 

 ancient than the diluvial. The remaining genera of mammiferous 

 animals can be identified with those now existing, or with such as 

 are found in diluvial and lacustrine deposits. The author next 

 notices the discovery of the mineralized remains of birds, chiefly 

 bones of the extremities of natatorial tribes, a solitary instance of a 

 similar discovery in America being the only one recorded. He was 

 not prepared to speak concerning the different kinds of fish, but he 

 stated their distribution — species of Squalus being found near Orford, 

 and what Agassiz conceives to be Platex, at Cromer. Among the 

 most remarkable is the Carcharias megalodon, the teeth of which 

 are found in Suffolk, equal in size to specimens frbm the tertiary 

 formations of Malta. He also alluded to the difference of the tes- 

 tacea in different parts of the crag, from which he was inclined to 

 infer there were several eras in its formation. No traces of the ex- 

 istence of reptilia have yet been detected, which would rather sup- 

 port the opinion of Dr. Beck and Deshayes, that the climate during 

 the crag epoch was analogous to that of the polar regions. — Prof. 

 Sedgwick stated, that he had been long aware of the existence of re- 

 mains of mammaha in the Norfolk crag, although this had been dis- 

 puted by Mr. Conybeare, in his work on the Geology of England 

 and Wales. He was rather inclined to consider the crag as all of 

 one epoch ; and Mr. Lyell had found existing species as numerous 

 in the lower as in the upper crag. With regard to Mr. Charles- 

 worth's idea of the extinction of the mastodon in England before the 

 formation of the diluvial beds. Prof. Sedgwick conceived that it was 

 reasoning from a negative fact, and that until more extensive search 

 had been made, no such inference could be fairly drawn. He also 

 mentioned that remains of the beaver were found in the alluvions of 

 Cambridgeshire, and that it might have existed in England a thou- 

 sand years ago. He was confident that no cause still in existence 

 could have produced the diluvium on the crag ; its whole appear- 



