LYMNZIDZ OF NORTH AMERICA. 375 
Limnophysa pingellii Tryon, Amer. Journ. Conch., I, p. 254, 1865. 
Limneus pingellii Kuster, Conch. Cab., p. 27, taf. 5, figs. 11, 12, 1862. 
Lymnaea vahlii var. pingelit DaLL, Alaska Moll., p. 75, fig. 55, 1905. 
Limnea vahlii var. nitida Mércu, Prod., No. 10 a, Amer. Journ. Concb., 
IV, p. 35, 1868. 
Limnea vahlii var. pingelii, aa solidula Morcu, Amer. Journ. Conch., IV, 
p. 35, 1868. 
Limnea arctica Wuiteaves, Nautilus, XIX, p. 3, 1905; Ottawa Naturalist, 
XIX, p. 65, 1905. 
Limnea palustris RANDOLPH, Nautilus, p. 109, 1899 (part). 
Sueti: Thin, cylindrical, ovate; periostracum dark reddish horn 
or brownish; sculpture as in vahlii; whorls 5-6, very convex; sutures 
deeply impressed ; spire short, as long as, or shorter than, the aperture, 
‘the apex obtuse and generally decorticated ; aperture ovate, somewhat 
dilated in some individuals; inner lip narrow; appressed to the um- 
bilical region, leaving a small chink; columellar callus wide, thin, white ; 
columella with a longitudinal thickening but with scarcely any twist. 
In some individuals the rest periods may be seen as light yellowish 
longitudinal streaks ; from 3 to 5 of these streaks may be seen on each 
shell. 
Length. Width. Aperture length. Width. 
15.00 ee 8.00 .... mill, Morch. 
13.75 7.75 6.50 3.50 ~~ St. Michaels. 
12.00 6.00 6.00 3.10 sf 
12.50 7.25 7.50 AXON Be 
12.50 7.10 6.50 4.00 “ a 
12.75 6.50 7.00 St na a 
10.00 5.50 4.50 500k es ! 
Type: Location not ascertained. 
Type LocaLity: Tank on the northern shore of Baal’s River, 
vicinity of Nepiset Sound, Greenland. 
Animat, JAw, Ravuta and Geniraria: Not recorded. 
Rance: (Figure 42). Western Greenland to western Alaska. 
A form of the Arctic and Hudsonian divisions of the Boreal life zone. 
Future research will doubtless connect the two widely separated areas 
on the map, and the race will probably be found to inhabit the Yu- 
konian, Mackenzian, Hudsonian and Greenlandian regions. 
RECORDS. 
ALASKA. 
St. Michaels (E. W. Nelson); flats near St. Michaels (Randolph) ; Dall 
River (Dr. I. T. White). 
BritisH AMERICA. 
YuxKon TERRITORY: Stewart River, near Mayo River (J. Keele; Whit- 
eaves). 
