$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 Sect ion, Academy of Natural Sciences, Philadelphia. 



ASSOCIATE EDITOR : 

 C. W. JOHNSON, Curator of the Wagner Free Institute of Science. 



Vol. XII. 



JULY, 1898. 



No. 3 



CONTENTS : 



PAGE. 



A NEW JAMAICAN LAND SHELL. By J. B. Henderson, Jr. (Illustrated). 25 



LAND SHELLS OF GUN CAY, BAHAMAS. By Henry A. Pilsbry. ( Illustrated). 26 



A NEW SPECIES OF CERES FROM MEXICO. By W. H. Ball. . . 27 

 SOME OBSERVATIONS ON THE GENITAL ORGANS OF UNIONID^J, WITH 



REFERENCE TO CLASSIFICATION. By Br. V. Sterki. (Concluded). 28 



A NEW UNIO. By Berlin H. Wright. 32 



RECENT PUBLICATIONS. . . . . . . 33 



GENERAL NOTES. . 36 



Published by 



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



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



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



