INTRODUCTION. vii 



Mr. Richard Cowling Taylor published, in the ' Philosophical Magazine,' 1822-24, 

 some observations on the Norfolk Cliffs, as well as a Paper, in the ' Geological 

 Transactions,' upon the Tertiary deposits of Norfolk and Suffolk ; some good figures 

 of Crag Corals were also given by him in the ' Magazine of Natural History,' 1830. 



In 1826, Mr. Robberds published some ' Observations on the Eastern Valleys 

 of Norfolk.' 



In 1833, 'An Outline of the Geology of Norfolk' was published by Samuel 

 Woodward the elder, in which there are some good figures of Crag fossils, from the 

 beds in the immediate neighbourhood of Norwich, relating only to the Mammali- 

 ferous Crag. 



'.->• 



The geological features of the upper Tertiaries of this country, more especially 

 those portions from which the shells here illustrated have been extracted, have been 

 ably delineated by Mr. Lyell, in his 'Principles 'as well as in his 'Elements of Geology;' 

 and also in a special Memoir, published in the ' Magazine of Natural History' for 1839. 



Mr. Charles worth also published a series of Papers in the 'Philosophical Magazine' 

 for 1835, in which the Crag Formation was separated into three different Periods, the 

 oldest of which he designated the " Coralline Crag," as expressive of its contents, that 

 Formation being in some places composed entirely of Zoophytic remains. The 

 succeeding Period, or "Red Crag," was so denominated from its peculiar ochreous 

 colour, the beds being strongly stained by large quantities of the hydrous oxide of 

 iron ; but it was considered as geologically distinct, on account of the absence of the 

 great mass of Zoophytes peculiar to the lower beds, as well as of the introduction 

 of a new group of Testacea. A further examination of what had previously been 

 considered as an extension of the Red Crag Formation into Norfolk, induced that 

 author to suspect the Crag of Norfolk to be of posterior age, and, as position in this 

 case was no guide to such determination, he appealed to the certain evidence of 

 zoological distinction, which presented a more recent aspect than either of the 

 preceding ; and as amongst its imbedded fossils are the remains of numerous 

 Mammalia, he gave to this Formation the title of " Mammaliferous Crag." These 

 terms are employed in the present work. 



In 1836, Mr. John Morris published some observations, in the 'Magazine of 



