LYMNJE1DJE OF NORTH AMERICA. 407 



ensis has probably been recorded under the name of palustris, and in 

 many collections may repose under the name of sumassi, binneyi or 

 solida. It is, however, a distinct species related to the catascopium 

 group. Mr. H. O. Hinkley collected the specimens. 



Galba gabbii (Tryon). Plate XLII, figures 32-36. 



Limnaa gabbii Tryon, Airier. Journ. Conch., I, p. 229, pi. 23, fig. 2, 1865; 

 Con. Hald. Mon., p. 109 (83), pi. 18, fig. 7, 1872. 



Limnophysa gabbii Tryon, Amer. Journ. Conch., I, p. 254, 1865. 



Limncea adelince var. gabbii Cooper, Proc. Cal. Acad. Sci., IV, p. 96, 1870. 



Limnophysa var. gabbii Cooper, Proc. Cal. Acad. Sci., IV, p. 173, 1870. 



Shell : Small, rather thin, ovate ; periostracum brownish, rather 

 dark in some specimens ; surface dull, with rather rough, close set 

 growth lines and fine impressed spiral lines ; surface frequently mal- 

 leated; nuclear whorls !%■ rounded, smooth, almost jet black in color; 

 similar in outline to those of jacksonensis ; whorls 5, rapidly enlarging, 

 flatly rounded; body whorl very large, flatly rounded; spire short, 

 broadly acutely conical ; sutures impressed but not deeply indented ; 

 aperture large, somewhat lunate, a trifle oblique, generally more than 

 half the length of the entire shell ; parietal wall with a thin callus ; in- 

 ner lip narrow, reflected, so as to cover the umbilical region leaving, 

 rarely, a very small chink ; outer lip with an internal varix ; axis slightly 

 twisted, causing a more or less distinctly marked plait. 



Length. 



Width. 



Apert 



ure ler 



igth. 



Width. 







13.10 



7.10 





8.00 





4.00 mill. 



Type. 





16.25 



9.10 





9.75 





4.75 " 



" 





14.75 



8.50 





8.50 





4.50 " 



" 





14.00 



7.00 





8.50 





4.50 " 



Clear Lake, 



Cal, 



11.00 



6.00 





6.50 





3.00 " 





" 



Types : Academy of Natural Sciences, Philadelphia, twelve speci- 

 mens, No. 58526. 



Type Locality : Clear Lake, California. 



Animal, Jaw, Radula and Genitalia : Unknown. 



Range : California. A species of the Californian region and of 

 the Transition and Upper Austral (Upper Sonoran) life zones. 



RECORDS. 



California: Clear Lake, Modoc Co. (Button; Gabb; Hemphill; Tryon; 

 Veatch) ; Sacramento Valley (Rowell) ; Islais Creek, San Francisco Co. 

 (Cooper); San Francisco Co. (Hemphill). 



Geological Distribution : Unknown. 



Ecology : Not recorded. 



Remarks : Gabbii somewhat resembles some forms of catascop- 

 ium but differs in having a more acute, flat-sided spire, a more elon- 

 gated aperture and a less distinctly marked plait on the columella. The 



