474 PKOCEEDIN'GS OP THE GEOLOGICAL SOCIETY. 



This gives a slight increase in the proportion of northern spe- 

 cies in the N^orwich Crag, while the proportion of southern species 

 shows a greater decrease, hut not more than might be dependent 

 on local coast conditions. The relative proportion of total British 

 species in the Red and I^orwich Crags respectively is as close as 

 67: 69, while the total northern forms show as 80 : 105, and southern 

 forms 150 : 104. Or, taking the species not now found living in the 

 British seas, their relative distribution in the three Crags is as 

 under : — 



Species now restricted to 



Total ,. ^ .. 



living species. Northern seas. Soutliern seas. 



NorwicliCrag 130 19 11 



Red Crag 216 23 32 



CoralUneCrag 264 14 65 



So that while the relative number of British species, as well as of 

 the extinct species, remains nearly uniform, there is a considerable 

 decrease of southern and some increase of northern species in the 

 Norfolk area. 



The relation of the two crags as shown by the Mammalian remains 

 is less conclusive ; but the dijQferences are no greater than we might 

 expect from the evidently different relations of the land to the 

 water in the two areas. The same Mastodon*, Horse, Hyaena, 

 and Felis occur in both ; and there is strong reason to believe that 

 the Elephant (meiidioncdis ?) is likewise found in the Eed Crag. 

 A Bear (arvernensis), and a Deer (megaceros), though not found in 

 the Norwich area, are found in the Suffolk Red Crag, and pass into 

 the Forest-bed, and must therefore have existed in the Norwich- 

 Crag period. 



After carefully weighing all these considerations, I must confess 

 that, as I see no sufficient reason for regarding any of the Norwich- 

 Crag Mammalia as extraneous fossils, I now cannot but look upon 

 all species common to the two Crag areas, together with those species 

 which, though not found in both Crag areas, are still found in one, 

 and occur again in the later-deposited Porest-bed, as really con- 

 temporaneous fossils proper to the Red and Norwich-Crag series. 

 This view is in the main in accordance with that arrived at by Dr. 

 Falconer, upon the evidence of the contemporaneous continental 

 Pliocene fauna. 



The Forest- and Elephant-bed inaugurate a condition of things 

 materially different from that prevailing during the Crag period. A 

 number of new Mammalia make their appearance, including the 

 Eleplias antiquus and var. priscus in numbers, two new species of 

 Rhinoceros, a Hippopotamus, two Bears, together with species of 

 Horse and Ox, and some small rodents of existing species. But the 

 marked feature of the period consists in the number and variety of 

 the Deer, no fewer than six species, several of them of very peculiar 



* As the occurrence of the nearly entire skeleton of the Mastodon at Horstead 

 shows that it lived in the Norfolk Crag area, I do not think that it can be looked • 

 upon as extraneous to the Red Crag. 



