CONTENTS. 



* 



Page. 



Letter to Professor Hayden 5 



Introduction: on the significance of paleontological science 7 



PART I. 



On the classification and distribution of the Cretaceous deposits of the West 15 



PART II. 



Descriptions of the Cretaceous Vertebrata of the West _.. 42 



1. Description of the localities and fauna 42 



2. Literature of the Reptilia '. 51 



?>. Descriptions of the Reptilia 53 



4. Literature of the Fishes 179 



5. Descriptions of the Fishes 180 



PART III. 



Synopsis of the known Cretaceous Vertebrata of North America. 245 



