PREFACE. XI 



the Ray Society and of the public. Any person who has 

 access to periodical works, whether British or foreign, which 

 appear to have been unnoticed by the compilers of the pre- 

 sent Catalogue, will confer a boon by extracting the titles of 

 the zoological and geological papers which they contain, re- 

 ferring to the volume and page of the original work, in the 

 form adopted in this volume. The titles of such Books also 

 as have been omitted in our list, or have been published sub- 

 sequently, especially those of rare provincial and otherwise 

 inaccessible tracts and pamphlets on Zoology or Geology, 

 will be exceedingly acceptable. All such titles should be 

 written on one side of the paper only, and may be addressed 

 to the Secretary, Dr. E. Lankester, 22 Old Burlington Street, 

 London. 



I wish it had been in my power to have given an exact list 

 of those periodicals, the titles of whose contents have been 

 wholly or partly extracted into this work, so that those who 

 are disposed to aid in the above object might at once see 

 whether any given periodical had already been made use of 

 or not. Unfortunately M. Agassiz omitted to keep such a 

 list ; and to enumerate those which have been consulted by 

 myself would have only partially remedied this defect. By 

 referring however to a few of the individual titles, as entered 

 in this volume, it will easily be seen whether the work in 

 which they are contained has been systematically consulted 

 or not ; and the List of the Abbreviations employed will also 

 assist this object. 



A person who was willing to devote his life to compilation 

 might no doubt have made this work more convenient for 

 some purposes by arranging it as a classed instead of an 

 alphabetical catalogue. Such a task was not, however, practi- 

 cable in the present case, but every one may to a certain ex- 

 tent make it into a classed catalogue for himself, by attaching 



