THK NAUTILUS. 1 1 1 



Limnaa palnstris Miill. 



Taken from a pond near Bitter Root river. Quite abundant, 

 several hundred specimens taken. Also taken in abundance in 

 standing and quiet waters in tlie creeks on Flatliead Indian reserva- 

 tion. At the upper end of Flatliead Lake there is a great deal of 

 marshy country tributary to the lake and to Flatliead river. In 

 the lowland bordering on the lake, which had been overflowed and 

 later dried off, large quantities of dead shells were observed. In- 

 deed the shells were so abundant one could not walk without mash- 

 ing large numbers. In still other places the shells were yet alive in 

 the sloughs, in great abundance. Along the Bitter Root river the 

 shells were living in the same waters with Aphxa hypnorum. Mr. 

 Earl Douglass collected a large series in the Madison lakes, southern 



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part of the State, in summer of 1900. 



Linmcea nuttalliana Lea. 



Abundant in the region with L. stagnalis L.. var. appressa Say, 

 L. palustris Miill., and P. trivolvis Say. A hundred or more speci- 

 mens secured. 



Limncea emarginata Say, var. innnfaua Elrod. 



Shell large, globose, thin and fragile; of a light horn color, in 

 many cases tending to light pearl gray; in many instances there is 

 an abrupt line between the lighter portion and the horn colored por- 

 tion, the lighter portion being next the aperture ; the last whorl con- 

 stituting about three-fourths the length of the shell ; malleations ob- 

 scure or absent, distinguishable in occasional specimens; lines of 

 growth fine, and quite regular ; spire short, consisting of three ob- 

 liquely twisted whorls and the nucleus ; suture well impressed ; 

 aperture about two-thirds as long as wide ; outer lip thin, acute, 

 inner lip reflexed near its junction with the columella. 



Length '27 mm. Greatest width 13.25 mm. Width of aperture 

 10.25 mm. Length of aperture 14.70 mm. Whorls, 5. 



The species is found sparingly in Sin-yale-a-min lake in the Mis- 

 sion range of western Montana, and abundantly in McDonald lake, 

 some 15 miles north of the former. A few were taken in Swan 

 lake, on the opposite side of the range. At Sin-yale-a-min lake an 

 entire afternoon was spent in securing a couple of dozen specimens. 

 The method was to row o\er to the lake outlet in the canvas boat, 



