iv PREFACE. 



store-rooms, to which this Guide does not refer. The process-blocks 

 are from photographs of actual specimens in the Museum, and were 

 prepared under my immediate superintendence. The Gruide lias 

 been written by Mr. E. Lydekker, F.R.S. Some of the woodcuts 

 are borrowed from the ' Cambridge Xatural History,' others are 

 from publications akeady issued by the Trustees. 



E. RAY LANKE8TEE. 



DiEECTOR. 

 British Museum (Natural History), 

 London, S.W. 



March 1th, 1906. 



