xiv TABLE OF CONTENTS. 



ARTICLE V. PALAEONTOLOGY OF THE UPPER MISSOURI : A REPORT UPON COLLECTIONS MADE 



PRINCIPALLY BY THE EXPEDITIONS UNDER COMMAND OF LlEUT. G. K. WAR- 

 REN, U. S. Top. Engrs., IN 1855 AND 1856. INVERTEBRATES. By F. B. 

 MEEK AND F. V. HAYDEN, M. D. Part I. Pp. 158, and five Plates. 

 (Published April, 1865.) 



Introductory Remarks ... vii 



I. Silurian Age. Potsdam Period ..... 1 



II. Carboniferous Age. Carboniferous Period ... .11 



III. Carboniferous Age. Permian Period . . . . .48 



IV. Reptilian Age. Jurassic Period ...... 66 



Index ......... 129 



Explanations of Plates. 



ARTICLE VI. CRETACEOUS REPTILES OF THE UNITED STATES. By JOSEPH LEIDY, M.D., 

 Professor of Anatomy in the University of Pennsylvania, Curator of the 

 Academy of Natural Sciences of Philadelphia. Pp. 140 and twenty plates. 

 (Published May, 1865.) 

 Introduction . . ... . . .1 



Sauria ......... 5 



Chelonia . . . . . . . . .104 



A Synopsis, in which an attempt is made to define more closely the Genera 



and Species of Reptiles whose remains are described in the preceding pages 1 1 5 

 Index ......... 121 



References to the Plates 123 



