CONTENTS. 



On the Crocodilian genus Perosuchus. By E. D. Cope 203 



Notice of American Species of Ptychodus. By Joseph Leidy, 



M.D 205 



Synopsis of the Extinct Batrachia of North America. By Ed- 

 ward D. Cope, A. M 208 



On Agaphelus, a genus of toothless Cetacea. By E. D. Cope.. 221 

 Observations on the occurrence of Cupriferous Ores in Texas. 



By Dr. F. A. Genth 227 



Notice of some American Leeches. By Joseph Leidy, M.D... 229 

 Notice of some remains of Extinct Pachyderms. By Joseph 



Leidy, M.D 230 



On some Cretaceous Reptilia. By E. D. Cope -. 233 



On the Origin of Genera. By Edward D. Cope, A. M 242 



