200 THE CHICAGO ACADEMY OF SCIENCES. 



ella and bicuspid lateral teeth ; Simpsonia, with tricuspid lateral teeth ; 

 and Stagnicola, with a strong spirally lined shell, a plicate columella 

 and a characteristic radula and genitalia. 



The name Galba was given by Schrank to a species of Lymncea 

 which has been referred to both the Buccinum truncatulum and the 

 Buccinum palustre of Miiller. Dr. Dall is probably right in selecting 

 truncatulum as the type, the description of both shell and animal agree- 

 ing very closely with truncatula. The name Stagnicola would be pre- 

 ferable for the genus name were it not that Galba has priority and 

 must be retained for the genus; Stagnicola, however, may be used as 

 a subgenus for the large shells with impressed spiral lines and plicate 

 columella. 



The name Limnophysa has been almost universally used for the 

 large, palustris-like Lymnaeas, but this is an absolute synonym of Stag- 

 nicola, which was published three years earlier. Leptolimnca may be 

 retained for those shells with a cylindrical shell, numerous whorls, 

 and a small aperture. The anatomy of this group is unknown. 



Galba includes the large majority of the species of our Lymnseids. 

 The shells are generally long and graceful, and some one of the species 

 is invariably a characteristic member of the fauna of almost any local- 

 ity in North America. They occur in almost countless thousands in 

 some localities. 



Subgenus GALBA Schrank, 1803. 



1803. Galba SCHRANK, Fauna Boica, III, pt. 2, pp. 262, 285. (Sole example 



Buccinum truncatulum Miiller, vide Dall). 



1865. Limnophysa BINNEY (part), L. and F. W. Sh. N. A., II, p. 38. 



1870. Limnophysa DALL (part), Ann. N. Y. Lye. N. H., IX, p. 349. 



1870. Limnophysa COOPER (part), Proc. Cal. Acad., Ser. i, IV, p. 96. 



1872. Limnophysa TRYON (part), Con. Hald. Mon., p. 87 (61). 



1872. Limnaa TRYON (part), Con. Hald. Mon., p. 87 (61). 



1876. Limnophysa MEEK (part), Rep. U. S. Geol. Surv. Terr., IX, p. 533. 



1884. Limnophysa TRYON (part), S. and S. Conch., Ill, p. 101. 



1885. Fossaria WESTERLUND, Fauna Pal. Reg., V, p. 49. (L. truncatula Muller). 

 1902. Fossaria WESTERLUND, Acta Soc. Sci. Slav. Merld., CLI, p. 118. 



1905. Galba DALL, Alaska Mollusks, p. 64. 



1908. Galba BAKER, Science, N. S., XXVII, p. 943. 



SHELL: Generally small, turreted, surface usually without spiral 

 lines; axis not twisted, forming a series of smooth, almost round pil- 

 lars from apex to umbilicus; columella without a plait; inner lip 

 usually forming a wide, smooth, spreading callus, which is turned back 

 against the parietal wall; umbilicus a small chink or roundly open; 

 outer lip thin, sharp, rarely forming, when adult, an internal rib just 

 within the edge (pi. XVIII, fig. 2). 



