'' / 



$1.00 per Year. ($1.12 to Foreign Countries.) lOcts. a copy. 



THE 



NAUTILUS 



A MONTHLY 



DEVOTED TO THE INTERESTS 

 OF CONCHOLOGISTS. 



EDITOR: 

 H. A. PiLSBRY, Conservator Conchological Section, Academy of Natural Sciences, Philadelphia. 



ASSOCIATE EDITOR : 

 C. W. Johnson, Acting Curator Wagner Institute of Science. 



Vol. IV. APRIL, 1891. No. 12. 



CONTENTS: 



MoLLUSKs OF Thompson's Lake, Illinois. W. S. Strode, M. D. 

 Description of New Species of Anctus and Oliva. John Ford. 

 Western Pennsylvania Shells. E. H, Ham. 

 Edible Mollusks of Rhode Island. Horace F. Carpenter. 

 On Pupa Rupicola Say, and Related Forms. Dr. V. Sterki. 

 American Association of Conchologists. (Contributed.) 



page. 

 13S 

 134 

 13& 

 137 

 139 

 143 



Published by 



H. A. PILSBRY, Editor, Academy of Nat. Sciences, Phihidelphia. 



C. W. JOHNSON, Manager, Wagner Free Institute of Science, Philad'a. 



Entered at Philadelphia Post-OflBce as second-class matter. 



FOREIGN AGENCIES:— London,Trubner & Co., 57 and .59 Ludgate Hil 

 Berlin, R. Friedlander & Son, 11 Carlstrasse. 



