INTRODUCTION. 



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 ba;se, and, further, that a Nodule- 

 bed with similar fossils iskuownto 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- 

 lifer ous 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 : — 



PlbiSTOCKne. — Arctic Freshwater Bed (with Salix polaris, 

 Betula nana, Spermophilus, c&c.) 

 "Leda-myalis- Bed (classed provisionally with 

 Pliocene). 



fUpper Fresh-"] 

 Forest | water I Gravels with Elepkas 



Bed -^ Estuarine y meridionalis at 



Series. | Lower Fresh- Dewlish, Dorset. 



[_ water 

 Weybourn Crag (and Chillesford Clay ?) 

 Chillesford Crag. 

 Norwich Crag. 

 Red Crag, Butley, &c. 

 Walton Crag (Lower Red Crag), 

 f St. Erth Beds. 



I Coralline Crag a'nd Lenbam beds. 

 ^ Box Stones and phosphate beds at the base of 

 I the lied and Coralline Crags [Nodule-b(!d] 

 [_ (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 Heid's Sutvey Membir 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. 



Newer 

 Pliocene. 



\ 



Older 

 Pliocene. 



A 2 



