LYMNIDZ OF NORTH AMERICA. Lil 
a single small, pure white shell dredged from deep water. The lower 
part was smashed by the dredge. The animal was pure white and 
consequently the black eyes were very conspicuous” (in letter). 
Future search will doubtless determine whether this peculiar shell 
is simply a case of albinism or an abyssal race of stagnalis. 
Lymneza stagnalis perampla (Walker). Plate XX, figures 7-9; 
pl. XXII, figure 5. 
Limnea stagnalis WaLKER, Nautilus, VI, p. 31, pl. 1, fig. 6, July, 1892. 
Lymnea stagnalis v. perampla Wa.Ker, Nautilus, XXII, No. 1, p. 8. pl. II, 
figs. 5, 6, May, 1908. 
This variety differs from the usual North American form, var. 
appressa Say, by its shorter, rapidly accuminating spire and larger, 
strongly shouldered body whorl; the first three whorls of the spire 
are slender and increase regularly in size; the penultimate whorl is 
disproportionately enlarged, swollen and subangulated by the flat- 
tening of the upper part of the whorl, which in the body whorl develops 
into a prominent shoulder (Walker). 
Aperture 
Length. Breadth. length. Breadth. 
45.50 26.00 28.00 18.00 mill. Type. 
45.00 23.75 26.00 17.00 ig 4 
49.00 26.50 30.00 15.50 “  Cotype. 
Tyres: No. 1834, coll. Bryant Walker; cotype, Chi. Acad. Sci., 
1 specimen No. 23924. 
Type Locatity: Houghton Lake, Roscommon County, Mich. 
ANIMAL, JAW, RaApuLA and GEeniTaLt1A: Not examined. 
RANGE: Michigan. A race of the Canadian region and of the 
Canadian life zone. 
RECORDS. 
MicuicaAn: Douglas Lake, Cheboygan Co. (Ferriss; Velie; Walker) ; 
Houghton Lake, Roscommon Co. (Walker). 
GEOLOGICAL RANGE: Unknown. 
Ecotocy: “All the specimens of stagnalis from Houghton Lake 
that I have seen, more than thirty, are of this peculiar form, which 
is apparently a well marked race” (Walker). 
It is interesting to note that in Marl Lake a small enlargement of 
Varl River, which connects Higgins and Houghton Lakes, the typical 
stagnalis appressa was the only form found. 
Remarks: As remarked by Walker, this variety seems to be a 
well marked race, easily separable from typical stagnalis appressa. 
It will probably be found in other localities in northern Michigan, and 
possibly in parts of Minnesota, Wisconsin and northern Ontario. 
