PREFACE. 



As it is presumed that the volumes of Palaeontology, 

 forming a part of the series of publications of the State 

 Geological Survey of California, will come into the hands of 

 persons who will not have the other parts of the work, it is 

 deemed proper to preface this volume by a brief notice of 

 the origin and organization of this Survey. This subject 

 will be entered into more fully in the first volume of the 

 geological portion of the Report; but it is suitable that a 

 sufficient account of the course and plan of operations of the 

 Survey should be prefixed to the first volume of each sepa- 

 rate department, to enable those consulting the publications 

 in that department to understand the scope of the work, and 

 to give due credit to those engaged in bringing together the 

 materials, of the special working up of which this volume 

 is the first instalment. 



The Act of the Legislature creating the office of State 

 Geologist and authorizing a Geological Survey of the State 

 of California, was approved April 21st, 1860 ; but operations 

 were not commenced until about the 1st of December of 



(vii) 



