10 EARLY MAN IN BRITAIN. [CHAP. i. 



IV. Pleistocene, in which living species are more 

 abundant than the extinct. Man appears. 



Characteristics. 

 Living species 



abundant. 

 Man appears. 



Y. Prehistoric, in which domestic animals and culti- 

 vated fruits appear, and man has multiplied 

 exceedingly on the earth. 



Man abundant. 

 Domestic animals. 

 Cultivated fruits. 



VI. Historic, in which the events are recorded in 

 history. 



Historical record. 



The Tertiary or Kainozoic strata were divided by Sir 

 Charles Lyell, 1 in 1833, into three great groups, accord- 

 ing to the percentage of existing mollusca, which was 

 presented in a comparison of 3000 fossil with 5000 Jiving 

 forms. The Eocene (770)9 dawn, Kawos new), or the 

 earliest group, contained about 3^ per cent of living 

 shells, and thus, to speak metaphorically, was charac- 

 terised by the dawn of the Testaceous fauna, now living 

 in the sea. In the Meiocene (/^etW less, KCUVOS) group 

 the existing forms were much more abundant, being 

 always less than 35 per cent. The upper group was 

 termed Pleiocene (TrXet&V more, /caivbs), because it pre- 

 sented from 35 to 50 and even 90 per cent of living 

 testacea. The vast number of fossil species which have 

 since been added to those which formed the basis of 

 this classification has not materially altered its value, 

 but merely rendered the strict definition of the per- 

 centages impossible. 2 The term Pleistocene (7rXet<7T09 

 most, /caLvbs) was subsequently applied by Sir Charles 

 Lyell to assemblages of fossil species in which there 

 was a still nearer approximation to existing nature. 



1 Principles, 1st edit., vol. iii., 1833. Antiquity of Man, 1st edit., p. 3. 



2 See also Dawkins' Preliminary Treatise, British Pleistocene Mammalia, 

 Palseont. Soc., 1878, pp. iv. v. 



