A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae) /
Hershler, Robert.
A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae) / Robert Hershler. - Washington, D.C. : Smithsonian Institution Press, 1994. - 115 p. : ill. ; 28 cm. - Smithsonian contributions to zoology ; no. 554 .
Companion to: Smithsonian contributions to zoology ; no. 554
A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae) / Robert Hershler. - Washington, D.C. : Smithsonian Institution Press, 1994. - 115 p. : ill. ; 28 cm. - Smithsonian contributions to zoology ; no. 554 .
Companion to: Smithsonian contributions to zoology ; no. 554