in the Tertiary Deposits of Norfolk and Suffolk. 41 



shelly strata with which geologists were already familiar. — 

 Never having detected the remains of mammalia in either of 

 the above-named deposits, and believing that the crag of Nor- 

 folk was merely an extension of the upper or red crag of Suf- 

 folk, the author, in common with Professor Phillips, and some 

 other geological writers, had thrown doubts upon the exist- 

 ence of the bones of elephants and other land animals, in the 

 tertiary beds of the former county, believing that their sup- 

 posed occurrence probably originated in the erroneous iden- 

 tification of diluvium with crag; the extremely superficial 

 character of the latter, and the abrasion to which it has, in 

 some places, been exposed, rendering a precise separation of 

 the two a matter, sometimes, of considerable difficulty. 



A recent examination, however, of Norfolk, has produced 

 a total change in the opinions previously entertained by the 

 author upon this subject; for he finds that not only are the 

 bones of land animals constantly found in the so-called " crag" 

 of that county, but that they are of most frequent occurrence 

 in those particular beds which furnish the strongest evidence 

 of tranquil deposition ; and further, the bones strictly belong- 

 ing to these beds of marine origin, can be at once distinguish- 

 ed from those of the overlying diluvial or lacustrine deposits, 

 by the peculiar chemical change which the former have un 

 dergone. The list of mammalia enumerated by the author, as 

 belonging to the tertiary period, include six or eight species 

 of Rodentia and Ruminantia, one of the genus Lutra, besides 

 teeth of the elephant, hippopotamus, and mastodon. Dr- 

 William Smith was the first who announced the discovery of 

 the mastodon in our own country; and though geologists 

 have generally refused to place it on the list of British fossil 

 Pachydermata, the existence of this genus has recently been 

 most completely established by the researches of Mr. Robert 

 Fitch and Mr. Samuel Woodward, of Norwich, and Captain 

 Alexander, of Yarmouth. 



The author, in the next place, proceeds to discuss the re- 

 lation which this mammiferous stratum bears to the two ter- 

 tiary deposits of the adjoining county, and shews that is not, 

 as he had anticipaied, an extension of the red crag of Suffolk, 

 but a deposit altogether distinct from it and the coralline, dif- 

 fering essentially from both, in the number and nature of its 

 organic contents. Its geographical limits are not confined to 

 Norfolk, since it may be traced from Norwich, to Aldeburgh 

 in Suffolk, overlying some part of the coral reefs in that most 

 interesting locality. It may be most advantageously examined 

 in the immediate neighbourhood of Norwich, at Southwold, 



