Monograph of the Fresh-Water Univalve MoUusca 

 of the United States. 



Family VIVIPARID^, H. and A. Adams. 



Geneka. 



* Operculum concentric. 

 ViviPARA, Montfort.* 



** Operculum concentric, with spiral nucleus. 

 LioPLAx, Troschel. 



Genus VIVIPARA, Montfort. 



(For description of shell and animal see 

 Haldeman, Paludina, p. 1.) 



In the year 1862 I proposed to divide this 

 genus into several subgenera, and these have 



* Lamarck's Vivtpare, 1809, cannot be quoted because 

 not Latinized. Montfort published in 1810. 

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