Uh WAi)HINGTON. L>. 



PROCEEDINGS 



AMERICAlSr PHILOSOPHICAL SOCIETY 



HELD AT PniLADELPllI\ FOR PROMOTING USEFUL KNOWLEDGE. 



Vol. XXXIII. January, 1894. No. 144. 



TABLE OF CONTENTS. 



PAGE 



Stated Meeting, January 5, 1S94 .....' 1 



Age of the Newark Brownstone. By Benjamin Smith Lyman 5 



Further on the Age of the Newark Brownstone. By Benjamin 



Smith Lyman 9 



Nagualism. A Study in Native American Folk-lore and History. 



By Daniel O. Brinton, M.D 11 



The Yolk Nucleus in Cymatogaster aggregatus Gibbons (with three 



plates). By Jesse W. Huhhard 74 



On the Fishes obtained by the Naturalist Expedition in Rio Grand« 



do Sul (with six plates). By E. D. Cope 84 



On the Structure of the Skull in the Plesiosaurian Reptilia, and on 

 Two New Species from the Upper Cretaceous (with one plate). 



By E. D. Cope 109 



Forests of Pennsylvania. By J. T. Rothrock 114 



Association : The Dominating Need of Man and the Keynote of 



Social Science. By Henry Carey Baird 134 



Stated 31eetbng, January 19, 1S94 141 



Stated Meeting, February 2, 1894 144 



Stated Meeting, February 16, 1894 146 



Slated Meeting, March 2, 1894 150 



Stated Meeting, March 16, 1894 155 



E^f" It is requested that the receipt of this number be acknowledged. 



It^" In order to secure prompt attention it is requested that all corre- 

 spondence be addressed simply "To the Secretaries of the American 

 Philosophical Society, 104 S. Fifth St., Philadelphia." 



Published for the Society 



BY 



MacCALLA & COMPANY, 



NOS. 237-9 DOCK STREET, PHILADELPHIA. 



