SECOND SERIES: PULMONATA. 



MANUAL 



OP 



ONCHOLOGY; 



STRUCTURAL AND SYSTEMATIC. 



WITH ILLUSTRATIONS OF THE SPECIES. 



BY GEORGE W, TRYON, JR. 



CONTINUED BY 



HENRY A. PILSBRY. 



CONSERVATOR OF THE CONCHOLOGICAL SECTION OP THE ACADEMY OF 

 NATUKAL SCIENCES OF PHILADELPHIA. 



Of THf A "Vol "VTT 



UNIVERSITY! Voi - v - x - 



HELICIDyE, Vol. V. 



PHILADELPHIA : 

 Published by the Conehologieal Section, 



ACADEMY OF NATURAL SCIENCES, COR. igTH AND RACE STS. 



1891. 



