PREFACE. Vll 



to acquire some knowledge of a subject of such vast 

 and universal interest. 



In carrying out the object which he has held before 

 him, the Author can hardly expect, from the nature of 

 the materials with which he has had to deal, that he has 

 kept himself absolutely clear of errors, both of omission 

 and commission. The subject, however, is one to which 

 he has devoted the labour of many years, both in 

 studying the researches of others and in personal 

 investigations of his own ; and he can only trust that 

 such errors as may exist will be found to belong chiefly 

 to the former class, and to be neither serious nor 

 numerous. It need only be added that the work is 

 necessarily very limited in its scope, and that the 

 necessity of not assuming a thorough previous acquaint- 

 ance with Natural History in the reader has inexorably 

 restricted its range still further. The Author does not, 

 therefore, profess to have given more than a merely 

 general outline of the subject ; and those who desire 

 to obtain a more minute and detailed knowledge of 

 Palaeontology, must have recourse to other and more 

 elaborate treatises. 



United College, St Andrews, 

 October 2., 1876. 



