PREFACE. 



Volume I of the Palaeontology of California was issued in 

 1864, the preface bearing date September of that year. It 

 contained descriptions of the Carboniferous and Jurassic fos- 

 sils by Mr. Meek, and of the Triassic and Cretaceous by Mr. 

 Gabb, and is illustrated by thirty-two plates. The present 

 volume is devoted to the Tertiary and Cretaceous palaeontol- 

 ogy, and is entirely the work of Mr. Gabb. At the time the 

 first volume of the Palaeontology was published — which was 

 also the first of our Keport — it was thought that the whole of 

 our material in this department of the Survey would be com- 

 prised in two volumes. Events have proved, however, as might 

 perhaps have been foreseen, that at least three volumes will 

 be required for the proper exposition of our palaeontological 

 results. The Cretaceous and Tertiary invertebrate material 

 alone requires a volume by itself, and for a third, and pos- 

 sibly a fourth, we have still such additions as have been made 

 to the Jurassic and Triassic, as well as all the fossil plants of 

 various ages, and the vertebrate remains, chiefly of fresh- 

 water and land animals, and of Tertiary age ; besides these, 

 are the microscopic fossil organisms, both marine and fresh- 

 water, which are interesting, and will require considerable 

 space for their illustration. 



In the preface of Volume I of the Palaeontology, a brief 



f vii ) 



