Wi Dp AL TL 
OF 
CONCHOLOGY: 
STRUCTURAL AND SYSTEMATIC. 
WITH ILLUSTRATIONS OF THE SPECIES. 
BY GEORGE W. TRYON, JR. 
CoNSERVATOR OF TH CONCHOLOGICAL SECTION OF THE ACADEMY OF NATURAL 
SCIENCES OF PHILADELPHIA, 
Voi: VE | 
CONIDA:, PLEUROTOMIDA. 
———$_—— 
PHILADELPHIA: A> 
Published by the Author, 
ACADEMY OF NATURAL SciENCES, Cor. ISTH & RACE STS. w 
1884. 
: | 
