SUBJECT-INDEX TO THE LISTS 

 OF GEOLOGICAL LITERATURE 



ADDED TO THE GEOLOGICAL SOCIETY'S LIBRARY 

 DURING THE YEARS 1920, 1921, & 1922 



The Lists of Geological Literature added to the Geological Society's Library 

 during the years 1920-1924 inclusive were published in the form of a list of 

 papers and separate books arranged alphabetically under the names of the 

 authors. The index to the subject-matter contained in the papers (which 

 had formed part of all the annual lists previously published) could not, for 

 financial and other reasons, be compiled and printed during these years. 

 Provision was made later, however, for repairing this omission and a subject- 

 index to the literature for 1923 and 1924 was issued in 1933. The index which 

 follows is for the years 1920, 1921, and 1922 and its publication completes the 

 Lists of Geological Literature added to the Geological Society's Library during the 

 years 1894-1934 inclusive. More exhaustive indexes to geological literature, 

 published elsewhere, have now superseded the Geological Society's annual 

 lists, which have, therefore, been discontinued. 



The attention of users of the index is directed to the following explanatory 

 notes : — 



I. This index follows the lines of those published in the Lists of Geological 

 Literature for the years subsequent to 1924. It differs from those published 

 previously in the following respects. 



1. Topographical Entries. Topographical entries have, in the main, 



been confined to such geographical divisions as counties, depart- 

 ments, states, etc. Obscure place-names mentioned in papers have 

 not been included, but the papers have been indexed under the 

 appropriate larger geographical unit. 



2. Pal/£ontological Entries. Names of fossils indexed are those which 



appear in the titles of papers or constitute an important part of 

 the paper indexed. The earlier practice of indexing the generic 

 names of all species figured in the papers has been discontinued, as 

 such genera and species are indexed in the Zoological Record published 

 annually by the Zoological Society of London. 



3. Maps. The maps indexed (under the heading " Maps ") are those 



which appear in papers or books included in the Author-lists for 1920, 

 1921, and 1922. Separately published maps (for example, sheets of 

 Geological Survey maps) do not appear in this index ; a list of such 

 maps received during each of those years will be found at the end of 

 the appropriate Author-list. 



4. Obituaries. Names of geologists of whom obituary notices have been 



published will be found indexed in the Author-list. They are not 

 repeated in the Subject-index. 



II. The figures 0, 1, and 2 have been used throughout the index to denote 

 the years 1920, 1921, and 1922 respectively. Authors' names following' the 

 figure 0 refer to papers by those authors included in the List of Geological 

 Literature for 1920 ; those following the figure 1 refer to papers in the fist 

 for 1921 ; and those following the figure 2 refer to papers in the list for 1922. 



0=1920 ; 1=1921 ; 2=1922. 



B 



