STRUCTURAL 



SYSTEMATIC 



CONCHOLOGY: 



AN INTRODUCTION TO THE STUDY OF THE 



MOLLUSOA. 



VOL. III. 



By GEORGE W. TRYON, Jr. 



CONSKRVATOR OF THK CONCHOLOGICAL SECTION OF THK ACADBMY OF NaTUKU. 



S01BNCK8 OF Philadelphia. 



PHILADELPHIA : 

 PUBLISHED BY THE AUTHOR, 



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



1884. 



Cfjpyright, 1884, by George vV. Tryou, Jr, 



