404 W. B. DAWKINS ON THE CLASSIFICATION OF THE 



Discussion. 



The Pjeiesident spoke of the great difficulties in the way of classi- 

 fication in the Tertiaries, whatever group of Invertebrata was chosen. 

 Prof. Seeley said that he had not quite understood in what 

 respect Prof. Dawkins's classification differed from those already 

 existing as founded on Mollusca. Much of the evidence on which 

 he had to work was, he thought, very fragmentary. This objection 

 especially applied to the older divisions of the Tertiary. He was 

 not convinced that the genera could be used for purposes of classifi- 

 cation as Prof. Dawkins had used them. The definitions which he 

 himself would use of genera or species would differ from those used 

 by Prof. Dawkins ; and so different results would follow. Another 

 objection that he had was to the assumption that animals had 

 become extinct from climatal causes ; for, historically, we know that 

 man has destroyed many forms of life in Europe, and thus the 

 differences between the Historic and Prehistoric faunas might be 

 explained. ; f 



Mr. Charleswoeth said the author had given no new factors to 

 aid in the classification of the Tertiaries ; for he had used the names 

 founded on the old molluscan classification. He thought there were 

 more extinct genera in the Crag than the author seemed to admit. 

 In the Crag the Polyzoa were more related to the Miocene, the 

 Mollusca to the Pliocene. 



Mr. Whitaker said that he did not see where Prof. Dawkins's 

 classification differed from the present one ; for the Lyellian terms 

 abounded in his paper, which should rather have been called "the 

 range and evolution of Mammalia in Tertiary times." Por himself 

 he doubted whether the Crayf ord brick-earths could be called Middle 

 Pleistocene and not Upper. Prof. Prestwich had long ago found 

 the Musk-sheep in the Thames valley, near Maidenhead, in beds of 

 much the same age as those at Crayford. As a working Tertiary 

 geologist, he did not see how to apply Prof. Dawkins's system ; for 

 though he often got plenty of shells, he had never found a single 

 mammalian remain in beds below the Pliocene. So how could he 

 classify by Mammalia? He thought the system proposed was un- 

 practical. If " doctors differ " as to the genera and species of 

 Mammalia, the classificatory value of the latter is doubtful. 



Rev. J. P. Plake said no doubt rocks in the field must first be 

 studied stratigraphically ; but the larger groupings were dependent 

 on the fauna contained. This, he thought, was the lino Prof. Boyd 

 Dawkins had adopted ; but he had not shown where his classifica- 

 tion differed from the received one. He thought, however, that the 

 Mammalia had already been used for classification of the Tertiaries. 

 The President remarked that, to his mind, the chief feature in the 

 paper was its history' of the Miocene fauna, which was so little 

 known in Britain. Whether this mode of classification was novel 

 or not, the way in which the facts were clearly massed was most 

 valuable. He would not himself reject either mode of classification; 



