PREFACE, vil 
clude such Geological treatises as contained any information 
on the structure or distribution of organic remains. But this 
definition embraced, in fact, nearly every existing geological 
work, and the labour of examining all such writings to ascer- 
tain whether they did or did not contain paleontological 
matter would have been so great, that it was thought better 
to extend the limits a little wider so as to include all works 
on descriptive Geology, whether they referred to organic or 
to inorganic phenomena. 
The first portion of the work contains a list, arranged geo- 
graphically, of all the known periodical or miscellaneous pub- 
lications which contain treatises on Zoology or Geology. As 
however it was in many cases impossible to make a personal 
examination of all such works, on account of their extreme 
rarity and limited circulation, it is probable that some of 
them may not in fact contain matter relevant to our purpose. 
This seems to be especially the case with the periodicals ot 
France and Italy, enumerated hereafter, many of which ap- 
pear from their titles to be either of a popular nature, or to be 
remotely connected with our subject-matter. We have how- 
ever preferred to err on the side of excess rather than of de- 
fect, especially as it may interest the student in other branches 
of science, to find here recorded the titles of many valuable 
periodicals whose existence was previously unknown to him. 
Nor must it be supposed that some Journals, whose titles 
have no apparent reference to Zoology or Geology, are here 
inserted without good reason. Many a valuable fact relating 
to those subjects lies buried in periodicals specially devoted 
to Chemistry, Meteorology and other physical sciences, and 
in the majority of instances the compilers have themselves 
ascertained such to be the case before they ventured to insert 
a title into their list. 
Under Periodical Works are included all serial publica- 
