SECOND SERIES: PULMONATA, 



MANUAL 



OF 



/ O 



STRUCTURAL AND SYSTEMATIC. 



WITH ILLUSTRATIONS OF THE SPECIES. 



BY GEORGE W. TRYON, JR. 



CONSERVATOR OP THE CONOHOLOGTCAT, SECTION OF THE ACADEMY OF NATURAL 



SCIENCES OF PHILADELPHIA. 



VOL. III. 



HELICID^:-VOL. I. 



PHILADELPHIA: 

 PUBLISHED BY THE AUTHOR, 



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



1887. 



