ie % 
A 
MONOGRAPH 
= OF THE 
FRESH-WATER UNIVALVE MOLLUSGA 
OF THE 
UNITED STATES, 
(IN CONTINUATION OF PROF. 8. 8S. HALDEMAN’S WORK, PUBLISHED UNDER 
THE ABOVE TITLE.) 
By GEORGE W. TRYON, Jr. 
TURBIDA, 
PHYSADZ, 
» 
PHILADELPHIA: 
PUBLISHED BY 
Tue ConcnotogicaL Szcrion or THE AcapEMy or NaTuraL Screncus, 
' N. W. corner of Broad and Sansom Streets. 
"NEW YORK: LONDON : 
B. Westermann & Co., 440 Broadway. Tribner & Co., 60 Paternoster Row. 
BERLIN : MADRID: 
Asher & Co., 20 Unter der Linden. C. Bailly-Bailliere, Calle del Principe. 
PARIS: 
| J. B. Bailliere et Fils, Rue Hautefeuille. 
be | af 
