OF NORTH AMERICA. 



In 1871, W. H. Dall published a revision of the Lymnaeids, and 

 under the subfamily Limnseinse recognized the following genera and 

 subgenera : 



Genus Limneea Lam. 



Subgenus Radix Mont. 

 Subgenus Limnophysa Fitz. 

 Subgenus Bulimnca Hald. 

 Subgenus Acella Hald. 

 Subgenus Pleurolimncea Meek. 

 Subgenus Limn&a Lam. 

 Genus Amphipeplea Nils. 

 Genus Erinna H. and A. Adams. 



In 1872, G. W. Tryon continued Haldeman's monograph of Lym- 

 nsea, recognizing the following groups : 



Genus Limn&a Lam. 



Subgenus Auricula Klein. 

 Subgenus Bulimnea Hald. 

 Subgenus Limnophysa Fitz. 

 Subgenus Leptolinmea Swains. 

 Subgenus Acella Hald. 



In 1884, the same author arranged the Lymnseids as follows irk 

 his Structural and Systematic Conchology : 



Genus Limnaa Lam. 



Subgenus Lymnus Montf. 

 Subgenus Radix Montf. 

 Subgenus Polyrhytis Meek. 

 Subgenus Bulimnea Hald. 

 Subgenus Limnophysa Fitz. 

 Subgenus Leptolimnaa Swains. 

 Subgenus Acella Hald. 

 Subgenus Pleurolimncea Meek. 

 Genus Amphipeplea Nilsson. 

 Genus Erinna H. and A. Adams. 

 Genus Lantzia Jouss. 



The treatment of the Lymnseids in the works of H. and A. Adams,. 

 Fischer, Gray, Kiister, Clessin, Westerlund and other European writ- 

 ers does not differ materially from that cited above. 



In 1905, W. H. Dall revised the Lymnseids of the northern part 

 of North America and presented the following synopsis which is,, 

 without doubt, the best treatment this group has received: 



Genus Lymn&a Lamarck. 

 Subgenus Lymncea S. S. 

 Section Lymnaa S. S. 

 Section Bulimnea Haldeman. 

 Section Radix Montfort. 

 Section Cyclolimnaa Dall. 



