HANNMBAL : CAI.IFORXIAX FRESHWATER MOLL0SCA. 



205 



0, resularly present ; L, local ; 

 I, introduced ; S, sporadic : 

 X, extinct ; K, characteristic. 



hwiinicola {Heathilla) erythro- 

 poma, Pils. 



. (HeathiUa) Cohimhiana, Pils. 

 . {HeathiUa) mimitissima, Pils. 

 tp-gulojjsis Xeradciisis (Stearns) 

 iiicinnatia Cinciiuiatiensis 

 ' (Antb.) 



VIVIPAEOIDE.E. 



Family Yn'iPARiD.E. 



liopoma Japonica (v. Mart.) 



{Cipancjopaludina) malleata 

 i (Eeeve) 



' VALYATOIDE.E. 



Family Valvatid.e. 

 'alvata tricarinata (Say) . 



s s s 



^ o 



s Is 



Extra-limital 

 Provinces. 





Pelecypoda, 23 ; Gastropoda, 47 ; total, 70 species and sub-species. 



Concluding Kemarks. 



"While it has been held as brief that unnecessary confusion of the 

 literature sliould be avoided by the introduction of as few innovations 

 of nomenclature as ])ossible, tlie fact has not been overlooked that 

 unless some standard code be followed the endeavours of that corps of 

 specialists whose Avork can only be compared with the wrecking-crew 

 on one of our railroads would shortly render the bulk of the data in 

 these pages wellni^h useless to the lay reader. The problem is less 

 a matter of the retention of certain old names whicli have been more 

 or less current in the literature, for both consistency and common 

 sense prohibit their use Avhere they liave been rendered futile by the 

 application of the genetic classi ti cation ; rather it resolves iiself into 

 permitting tlie establishment of unfamiliar names for a species several 

 times successively, or establishing one once and, let it be hoped, for 

 all time. 



Under the circumstances the writer has given as much care to the 

 selection of the names to be used for the species as in determining 

 tiieir limits and relationships, and only lack of the necessary literature 

 has prevented even more extensive revisions. The provisions and 

 recommendations of the International Code have ordinarily been 

 accepted in deciding upon the validity of names. The frequency that 

 these do not cover the questions at issue has led to the adoption of 

 several additional rules, the more important of which may be noted. 

 Tiie numbers apply to the sections of the Code affected. 



