142 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



L, Tryonii, Lea, in Tryon, 1865; L. Tryoniana, Lea, 1866; 

 L. (^Limnophysa) Shurtlejfi, Tryon, 1866 (syntonic form) ; 

 L. contracta. Currier, 1872 (syntonic form); L. Californica, 

 Sowerby, 1872 (syntonic form); L. interstriata, Sowerby, 1872 

 (syntonic form) ; L. palustris, var. septentrionalis, ' Clessin MS.,' 

 Kobelt, 1880; Leptolimncea ' Kirtlandiana^ Lea', Keep, 1888 

 (syntonic form) ; Limn/ea 2>(tlustris Michiganensis, Walker, 1892 

 (syntonic form) ; L. reflexa Jolietensis, F. C. Uaker, 1901 (syntonic 

 form) ; Z. Zeai, F. C. Eaker, 1907 (syntonic form) ; Z. Danielsi, 

 F. C. Baker, 1907 (syntonic form) ; Galha palustris AIpe7iensis, 

 F. C. Baker, 1911 (syntonic form); G. palustris Blachleyi, F. C. 

 Baker, 1911 (syntonic form); G. neopalustris, F. C. Baker, 1911 

 (syntonic form). 

 Sbell of moderate size, spire well elevated, whorls moderately 



inflated, sub-perfoi\ite, aperture somewhat narrowly auriculiform, 



columellar fold well developed ; habitat lakes, marshes, and sluggisli 



streams. 



Boreal portions of Paloearctic and Nearctic "Regions. Entire 



Californian Province except Los Angeles and Arizona Systems. 

 Quaternarj' : Loess of eastern States ; Lahontan Lake beds, Nevada ; 



Bonneville Lake beds, Utah ; post-Glacial deposits of Vancouver and 



San Juan Islands. 



Lymn^a columella, Say. 



Lymnaa columella, Say, 1817 ; Limncea chah/hea, Gould, 1840 ; L. casta, 

 Lea, 1841 ; L. Fra^icisca, Poey, 1858; L. columella, var. Chanipioni, 

 von Martens, 1899. 



Shell rather small for group, fragile, spire somewhat elevated, 

 whorls but little inflated, imperforate, aperture sub-succiniform, 

 columellar fold incipiently developed ; habitat quiet waters. 



St. Lawrence Basin and Hudson Bay drainage south to Florida 

 and Texas (but absent from Great Plains and east slope of Bocky 

 Mountains), American Province; Gulf of Mexico and Pacific drainages 

 south to Panama, Mexican Province ; Antillean Province. 



Quaternary : Loess of eastern States. 



A primitive species. A rather rudimentary columellar fold is 

 developed, while more or less of the succiniform build of tlie ancestral 

 Acellinse is still retained. 



Lymjj-^a reflexa (Say). 



Lymneus reflexus. Say, 1821; L. cxilis, Lea, 1837; L. Kirtlandiana, 

 Lea, 1841; Limncea lanceata, Gould, 1848; L. reflexa scalaris, 

 "Walker, 1892, not L. scalaris, Biaun, 1853; Z. reflexa Walkeri, 

 F. C. Baker, 1902; Z. refexa Remphilliana, F. C. Baker, 1904. 



Shell of moderate size, solid, spire attenuate, whorls but little 

 inflated, imperforate, aperture succiniform, columellar fold imperfectly 

 developed ; habitat lakes and sluggish streams. 



St. Lawrence drainage and Mississippi Basin above junction of 

 Ohio and Mississippi Bivers, American Province. 



Quaternary : Loess of eastern States. 



