PREFACE. 



, the fourth volume of the Catalogue of the Collection of Books, Maps, 

 &c., in the Natural History branch of the British Museum, brings the series 

 of entries under the authors' names down to the end of the letters " SN." The 

 first sheet was passed for press in October 1910. 



The lines on which it has been prepared have been fully set forth in the 

 " Introduction " to the first volume. 



Thanks for assistance in its production are due, not only to the persons 

 already mentioned in the Preface and Introduction to the first volume and in the 

 Preface to the third volume, but also to Mr. W. D. LANG, who, towards the close 

 of the volume, has acted for Geology, and to Dr. W. T. CALMAN, who on several 

 occasions has acted for Zoology. 



L. FLETCHER, 



Director. 



BRITISH MUSEUM (NATURAL HISTORY), 

 May 31st, 1913. 



