NORTH AMERICAN PLESIOSAURS. 



PART I. 



BY SAMUEL W. WILLISTON. 



CONTENTS. 



Introduction, .......... 



Bibliography and catalogue of North American Plesiosaurs, 

 Dolichorhynchops osborni WilHston. I)escrii)tion of skeleton, with restor 

 at ion, ........... 



Ciraoliasaurus snowii Williston, Destription of skull and neck, 

 Brachauchenius lucasii Williston. Description of skull, vertebrae and ribs 

 Polycotylus latipinnis Cope. Description of paddle, 

 l'olycotylus ischiadicus Williston. Description of pelvis, . 

 Plesiosaurus gouldii Williston. Description of dorsal vertebra, 

 Propodial hones of young Plesiosaurs from the Cretaceous of Kans; 

 A peculiar food-habit of the Plesiosaurs, ..... 



Plates 1 to XX IX 



Pagb 



3 

 7 



13 



5- 

 57 

 6 7 



72 

 T- 

 73 

 75 

 79 



