SKCOND SERIES: PULMONATA. 



MANUAL 



OF 



ONGHOLOGY: 



STRUCTURAL AND SYSTEMATIC. 



WITH ILLUSTRATIONS OF THE SPECIES. 



BY GEORGE W. TRYON, JR. 



CONTINUATION BY 



HENRY A. PILSBRY, 



CONSERVATOR OF THE CJNCHOLOGICAL SECTION AND PROFESSOR OF MALACOLOGY 

 IN THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA. 



Vol. IX. 



(HELICID^E, VOL. 7.) 



GUIDE TO THE STUDY OF HELICES. 



PHILADELPHIA : 

 ^Published by Concliological Section 



ACADEMY OF NATURAL SCIENCES, 

 OF PHILADELPHIA. 



1894. 



LIBRARY 



UNIVERSITY OF CALIFORNIA 

 DAVIS 



