TNTEODUCTION. 3 



Little need be said regarding the sub-divisions of the Pliocene 

 strata, as these are fully described by my colleague, Mr. Clement 

 Reid, in his Survey Memoir on '' The Pliocene Deposits of 

 Britain," 1890, but attention may be directed to the fact that by 

 far the larger part of the Vertebrate remains which are said to be 

 from the Red Crag really come from the Nodule-bed (Bone-bed of 

 some authors) which occurs at its base, and, further, that a Nodule- 

 bed with similar fossils is known to occur also under the Coralline 

 Crag. Many of the fossils from the Nodule-bed have been un- 

 doubtedly derived from the denudation of Eocene strata, while others 

 seem to be the remanie of Pliocene beds older than the Coralline 

 Crag, but of which no traces are known to occur in Britain. It has 

 been suggested that most of Nodule-bed Vertebrates have been 

 derived from Miocene strata, but there seems little evidence to 

 support such an idea. Many Vertebrate remains have been found 

 actually in the Coralline Crag and Red Crag above the Nodule- 

 bed, and this fact will be duly noticed in the description of the 

 species. The same is the case with the Norwich Crag, many 

 specimens being obtained above the Basement Bed, or Mamma- 

 liferous Stone -bed. 



The following table of British Pliocene deposits is taken from 

 the Survey Memoir by Mr. Clement Reid, and will serve to in- 

 dicate the horizons from which the fossils have been derived : 



PLEISTOCENE. Arctic Freshwater Bed (with Salix polaris, 



Bctula nana t Spermophilus, <&c.) 

 pLeda-myalis Bed (classed provisionally with 

 Pliocene). 



f Upper Fresh-"] 



Forest | water | Gravels with Elephas 



Bed <J Estuarine [> meridionals at 

 NEWER I Series. | Lower Fresh- I Dewlish, Dorset. 

 PLIOCENE. M L water 



Weybourn Crag (and Chillesford Clay ?) 

 Chillesford Crag. 

 Norwich Crag. 

 Red Crag, Butley, &c. 

 Walton Crag (Lower Red Crag). 

 "St. Erth Beds. 



Coralline Crag and Lenham beds. 



OLDER BQX g tones an( j phosphate beds at the base of 



PLIOCENE. j the Ked and Corall i ne Crags [Nodule-tod] 



[_ (with remanie early Pliocene fossils). 



A list of Works on Pliocene Vertebrata, supplementary to that 

 given in the Forest-bed Memoir, will be found on page 124, 

 but for fuller Bibliographies relating to Pliocene geology, the 

 reader is referred to Mr. Clement Reid's Survey Memoir above 

 mentioned ; also to Mr. H. B. Woodward's Memoir, The Geology 

 of the Country around Norwich, 1881 ; and to that by Mr. W. 

 Whitaker, The Geology of the Country around Ipswich, &c., 1885. 



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