CONTENTS. 



Pagf. 



Editorial Notes. J 59 



VIII. An Undetermined Element in the Osteology of the 



Mosasauridae. By W. J. Holland. .... 162 

 IX. The Gastropoda of the Chazy Formation. By Percy 



E. Raymond l68 



X. A Further Occurrence of Wynnea Americana in 



Pennsylvania. By Otto E. Jennings. . . . 226 

 XI. A Preliminary Account of the Pleistocene Fauna 

 Discovered in a Cave Opened at Frankstown, 

 Pennsylvania, in April and May, 1907. By W. 



J. Holland 22 ^ 



XII. Description of Vertebrate Fossils from the Vicinity 



of Pittsburg, Pennsylvania. By E. C. Case. . 234 



XIII. Notes on Ordovician Trilobites : Illaenidae from the 



Black River Limestone near Ottawa, Canada. 



By Percy E. Raymond and J. E. Narraway. . 242 



XIV. Rhinoceroses from the Oligocene and Miocene De- 



posits of North Dakota and Montana. By Earl 



Douglass 2 5 6 



XV. Fossil Horses from North Dakota and Montana. By 



Earl Douglass 26 7 



XVI. Some Oligocene Lizards. By Earl Douglass. . .278 

 XVII. Description of the Type Specimen of Stenomylis 



gracilis Peterson. By O. A. Peterson. . . . 286 

 XVIII. Brief Descriptions of Some New Species of Birds from 

 Costa Rica and a Record of Some Species not 

 Hitherto Reported from that Country. By M. 

 A. Carriker, Jr 3° ' 



