PREFACE. 



THE recent removal of the Geological Collections from the over- 

 crowded apartments of the British Museum in Bloomsbury to the 

 new and spacious galleries of the present building, has afforded 

 ample convenience to the scientific staff of the Department to 

 carefully examine and re-arrange the entire Collection a work 

 upon which they are still engaged, and one that must necessarily 

 occupy many years to complete. 



One result of the re-arrangement has been to bring into greater 

 prominence the need, long felt, of a series of Descriptive Catalogues 

 of each class of Fossil Eemains, suited to the wants of the scientific 

 worker, in the same manner that it is hoped the Guide-books 

 satisfy the requirements of the ordinary visitor. 



The present volume, which has been most carefully prepared by 

 Mr. R. Lydekker, forms Part I. of a series intended to embrace the 

 whole of the Fossil Vertebrata. 



Catalogues of other Classes have been already printed or are 

 now in course of preparation ; and it is confidently hoped that, 

 before many years have elapsed, similar records of the entire 

 Geological Collection will have been published. 



HENRY WOODWARD. 



British Museum 



(Natural History), 



Department of Geology, 



January 1, 1885. 



