SECOND SERIES: PULMONATA. 



MANUAL 



OF 



CONCHOLOGY 



STRUCTURAL AND SYSTEMATIC. 



WITH ILLUSTRATIONS OF THE SPECIES. 



BY GEORGE W. TRYON, JR. 



CONSERVATOR OF THE CoNrHOLOGTCAi, SECTION ov THB ACADEMY OP NATURAL 

 SCIENCKS OF PHILADELPHIA. 



VOL. III. 



HELICID^:-VOL. I. 



PHILADELPHIA: 

 PUBLISHED BY THE AUTHOR, 



Academy of Natural Sciences, Cor. 19th Sf Race Sts. 



1887. 



