140 PROCEEDIXOS OF TUE JIALACOLOGICAL SOCIETY. 



in tlie American Province, wliile of the species in the latter region 

 but four are absent from the area under consideration. This extent 

 of distribution is without doubt dependent upon the adaptability of 

 the species to a variety of surroundings. Z. Cooperi and L. truncatula 

 may be noted as examples ; the former is practically confined to 

 mountain streams, and unknown except in the Coast Ranges and 

 adjacent valleys between San Francisco and Point Conception, 

 California. Z. truncatula, on the other hand, occurs in a wide variety 

 of situations, marshy borders of lakes, moist banks of streams, and 

 even such artificial situations as greenhouses ; it is un(juestionably 

 the most extensively distributed member of the family. 



Owing to the chaotic condition of the species of this genus in recent 

 literature, it has been considered wise to include a brief account of 

 each of the valid recent American Province forms. Only a few more 

 prominent synonyms are mentioned, and no attempt is made to note 

 the numerous mistaken identifications resulting from certain ' New 

 School' writers using utterly worthless characters in specific dis- 

 crimination. In case of doubt Binney's Land and Fresh-ivater Shells 

 of North America may usually be taken as a guide in determining the 

 particular species the writer refers to. 



Li'JixiEA sTAGXALis (Liuue). 



Helix staffnalis, Linne, 17.58 ; Lymneus appressus, Say, 1821 ; Limnceus 



speciosus, Ziegler in llossniassler, 1835 ; Limnma '■jugularis, Say', 



Haldeman, 1841; Z. /e/)/f/rt, Gould, 1847 (juvenile) ; L.stagnalis, 



var. occidentalis, Hemphill, 1890 (syntonic form) ; Z. stac/nalis 



Sanctcemarice, Walker, 1892 (syntonic form) ; Z. stagnalin, var. 



Uigleyi, F. C. Baker, 1905 (syntonic form) ; Z. stagnalis, var. 



perampla, Walker, 1908 (syntonic form) ; Z. staf/nalis Lilliance, 



F. C. Baker, 1910; Z. sfagnalis Wanatchensis, 'Hemphill MS.,' 



F. C. Baker, 1911. 



Sliell large, spire acuminate, whorls but slightly inflated, imperforate, 



aperture sub-succiniform, columellar fold pronounced ; habitat lakes 



and marshes. 



Boreal and Arctic portions of Palaearcttc and Nearctic llegions. 

 Yukon, Alaska, Fraser, Columbia, Utah, Colorado (locally), Nevada, 

 Klamath, and Coast llange (locally) Systems. 



Quaternary : Loess of eastern States ; Lahontan Lake beds, Nevada ; 

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

 Island. 



Lyiixj:a adkicclaria (Linne). 



Helix auricularia, Linne, 1758 (sj-ntonic form) ; JBuccinum perecjrum, 

 Miiller, 1774; Lymncea catascopiuni. Say, 1817; Lymneus emar- 

 ginatus, Say, 1821 (syntonic form) ; L. pingtiis, Say, 1825 (syntonic 

 form) ; Limncea pallida, Adams, 1840; Z. decollata, Mighels, 1841 

 syntonic form) ; Z. ampla, Mighels, 1843 (syntonic form), not 

 Gulnaria ampla, Hartm., likewise = auricularia, L. ; Limnceus 

 Ontariensis, ' ^luhlfeldt ]MS.,' Iviister in Chemnitz, 1862 (syntonic 

 form); Limneea Sumassi, Baird, 1863 {partim, front view); 



