$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. PILSBRV, Conservator Conchological Section, Academy of Natural Sciences, Philadelphia. 



ASSOCIATE EDITOR : 

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



Vol. XII. 



JUNE, 1898. 



No. 2 



CONTENTS : 



PAGE. 



A LIST OF LAND AND FRESH WATER SHELLS OF ENGANIO WITH DESCRIP- 

 TIONS OF NEW SPECIES. By John B. Henderson, Jr. . . 13 



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



REFERENCE TO CLASSIFICATION By Dr. V. Sterki. . . .18 



DESCRIPTION OF A NEW HELIX. By C. F. Ancey 21 



NOTICES OF NEW SPECIES AND VARIETIES OF AMERICAN LAND SHELLS. 



By Henry A. Pilsbry 22 



NOTES AND NEWS. . . 23 



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. 



