FAMILY LYMN^ID^ 



67 



pillar gyrate, pervious, in the early whorls widely so, a condition 

 concealed in the adult. 



Tliis form grows in a region containing little lime, and the shells 

 are extremely thin and often eroded into holes, which exhibit the 

 peculiarities of the axis by which the species is relegated to the typical 

 Lymnaeas, though externally it has much the appearance of a small 

 Radix. The species has been figured in the newer portion of the 

 Conchylien Cabinet, but I have not the reference at hand. 



Adults measure : 



Height. 

 26.5 

 ;4.o 

 17.0 



Max. Diam. 

 .6.5 

 13.0 



Height of Aperture. 

 16.S 

 14.0 

 II. 2 



Width. 



10.5 



9.2 



7-S 



* Lymnaea lepida Gould. 



IJtiinaa lepida (iouLD, Proc. Boston Soc. Nat. Hist., 11, p. 

 figs. 141, 14111, 1852. — 



Whorls. 



4 



;il, 1847 ; Moll. 



p. 29, hg. 33, 



U. S. Expl. Exp., p. 121, 

 BixNEV, Land and Fw. Sh. N. Am. 

 1865. 



Range. — Lake Vancouver, Oregon (Wilkes) ; near 



Challis, Idaho (Merriam) I 



A species existing near the Ixnuulary and doubtless 



to be found in southern British Columbia. 



Gould. 



* Lymnaea (Bulimnea) megasoma Say. 



Lymnaus nifgasom us Sa\ , Rep. Long's Exp., 11, p. 263, pi. xv, fig. 10, 1824.— 

 KiJSTER, Conch Cab., ed. 11, Limncea, p. 36, pi. vi, figs. 20, 21. 



Limnea megasoma Haldeman, Mon. Limn., p. 13, pi. 



Ill, figs. 1-3, 1841. — Whitfield, Bull. Am. 



Mus. Nat. Hist. N. Y., i, No. 2, p. 29, pi. v, 1882. 



Limnaa megastoma SowERBV, Conch. Icon., xviii, pi. 



II, fig. 12, 1872. 

 Limnaa viet^a/osoma Sandberger, Conch, d. Urw., p. 

 581, 1873. 



Range. — Northern New England, Canada and 

 British America to Lat. 57° X. 



Lake Superior! Vermilion Lake, H. B. T. ; to 

 Etchimaniish Lake, in Lat. 57° between the Nel- 

 son River and the Height of Land, Kcewatin ; 

 Bois Blanc Lake, Manitoba ! 

 The British American localities are cited from the literature, and 

 except the last I have been unable to verify them by an examination 

 of authentic specimens. 



Fig. 44. LymntBa 

 megasoma Say. 



