60 BRITISH AND EUROPEAN FOSSIL MASTODONS. 



that the identification, either way, whether as Miocene or 

 Pliocene forms, must be regarded as little more than approxi- 

 mative. 



There are other considerations which corroborate the Plio- 

 cene view of the Mammalian fauna of the Crag. The debate- 

 able species referred by Prof. Owen to a Miocene origin all 

 belong to genera that are common to the Miocene and Plio- 

 cene periods, such as Mastodon, Rhinoceros, Tapirus, Sus, 

 Cervus, and Felis. But of the more remarkable types which 

 are limited to the upper Miocene deposits, and which abound 

 in them all over Europe, such as Dinotherium, Ghalicotherium, 

 Aceratherium, Anchitherium, Amphicyon, &c, not a single 

 remain has ever been cited as having been found in the Crag 

 deposits. The question naturally arises, how does it happen, 

 if the majority of the Red Crag Mammalia are Miocene, that 

 there has been this selective admixture of species of long- 

 termed ' Miocene ' genera in the Crag, and why the exclusion 

 of the strictly characteristic genera ? 



Another view may be taken, that, as the Red Crag contains 

 Fish and Crustacean remains which have been inferred to 

 have been washed out of denuded Eocene deposits, so the 

 Pliocene sea-bottom of the Eed Crag may have had Miocene 

 mammalian remains washed into it, thus causing an extrane- 

 ous admixture among the Pliocene mammalian fossils. But 

 it may be asked in reply, where are the Falunian deposits, in 

 proximity with the Crag in England, from which such a 

 washing-in could have taken place? And, if they were 

 transported from a distance, they ought to show marks of 

 abrasion from rolling, which, so far as my observation goes, 

 are not seen in a great many of the Red Crag Mammalia to 

 which a Miocene origin has been attributed. Many flattened 

 pieces of bone, exhibiting a high vitreous polish, and bearing 

 palpable marks of having been long rolled in the sea among 

 shingle, have unquestionably been met with in the Crag ; 

 but it does not necessarily follow that they were all washed 

 out of an older deposit. It is intelligible that the effect 

 may have been produced by attrition caused by the waves of 

 the Crag-sea upon bones of animals of the same geological 

 period. 



It now remains to consider how far the Cetacean fossils of 

 the Crag are in accordance with the inferred Pliocene cha- 

 racter of the Land Mammalia. Professor Owen has described 

 ' Cetotolites ' of five species of Balcenidoe from the Red Crag. 

 He states (Brit. Foss. Mam., p. 527), that they ' appear to 

 have been dislodged from a subjacent Eocene deposit ; ' and 

 the same opinion is repeated in the note appended to the 



