PREFACE vii 



enlighten, though with a faint gleam, those who desire 

 some explanation of the enthusiasm with which Palae- 

 ontologists pursue their research. 



The second part is designed to give an epitome of 

 the sequence of evolution as it has been unfolded in 

 geological time. In the small compass of this Intro- 

 duction to the Science there has been no space for the 

 biological diagnoses that are necessary to make such 

 an account intelligible. In consequence, it has seemed 

 advisable to follow, in the main, the classification 

 adopted in the latest and most comprehensive textbook 

 of Palaeontology available in the English language. 

 Except in the case of Echinodermata (which are dis- 

 cussed on the basis supplied in vol. iii. of Lankester's 

 Treatise on Zoology), the various phyla are arranged 

 in accord with the scheme given in the second edition 

 of Zittel-Eastman's Textbook of Palaeontology ', vol. i. 

 The section is, in effect, a kind of condensed guide to 

 that remarkable work. Although the present author 

 has had occasion rigorously to suppress his own 

 opinions in thus conforming to the views of others, 

 the sacrifice involved seems worth while. In a multi- 

 tude of counsellors there may be safety, but there is 

 sure to be confusion. For a beginner, any one scheme 

 is better than two. 



A via media is often recommended as a safe course, 

 but in truth such a path is full of pitfalls and beset with 

 thorns. Scylla and Charybdis, and the more familiar 

 dangers of the Devil and the Deep Sea, make the 

 attempt of such a passage almost foolhardy. To such 

 fellow-workers as may complain that their favourite 

 aspects of the Science are ignored or slighted, I will 

 apologize when they have succeeded where I have 



