68 THE NAUTILUS. 



OUTLET OF LONG LAKE. 



Galba randolphi (Baker). Half-grown and typical. 



Galba vahlii ("Beck" Moller). 



Planorbis similaris Baker. 



Two young individuals (three whorls) of a small Planorbis 

 are indistinguishable from specimens of similaris of the same 

 size from Colorado. They are not like parvus from near Phila- 

 delphia, having a less number of whorls in specimens of the 

 same size, and the base lacks the reamed-out appearance so 

 characteristic of typical parvus. The two localities are widely 

 separated although the ecological and general climatic condi- 

 tions are the same, the Colorado specimens occurring in a lake 

 at an altitude of 8575 feet (see Bull. Amer. Mus. Nat. Hist., 

 Vol. XLI, p. 532, 1919). This small Planorbis will doubtless 

 be found in many places between these extreme localities, when 

 it is discriminated from parvus, 



Pisidium species. 



Sterki says of this Pisidium, of which only four specimens 

 were collected, " unknown to me; probably immature." 



SAINT ANNE LAKE. 



Galba randolphi (Baker). Half-grown specimens. 



Galba vahlii ( " Beck " Moller). 



The lymnaeids referred to vahlii were at first thought to be 

 referable to palustris. The generally thinner, almost paper-like 

 shell and the wide columella callus without well-marked plait 

 seem to place them rather under vahlii. The spire in nearly all 

 of the specimens is very long and the whorls are inclined to be 

 flat-sided, differing in this respect from typical vahlii. This 

 species, like the protean palustris, of which it is a near relative, 

 probably exhibits a wide range of variation. 



Valvata lewisii helicoidea Dall. 



A single specimen of Dall's variety of Valvata lewisii occurred 

 with the material from Saint Anne Lake. It corresponds in 

 every way with the original description and figures (Alaska 

 Mollusks, p. 123, pi. ii, figs. 1, 2) but is smaller than the speci- 

 men figured by Dall. The measurements of the Saint Anne 

 Lake specimen are: height 2.2; greatest diameter 4 mm. The 



