156 THE CHICAGO ACADEMY OF SCIENCES. 
form “is characteristic of the quieter waters of the long, narrow har- 
bors which are such a remarkable feature of the island’ (Walker). 
Typical lilliane lives on a wave-beaten shore, and this precarious en- 
vironment has caused the aperture to become enlarged to provide for 
the larger foot to enable it to retain its hold on submerged objects. 
The Isle Royale form, living in quieter water, has not developed the 
large aperture of the Tomahawk Lake shell. 
The Tomahawk Lake shells vary to some extent, those inhabiting 
the quieter bays having a longer spire and a smaller aperture. These 
shells closely resemble the Isle Royale specimens and also clearly indi- 
cate relationship with appressa. Specimens referable to appressa were 
collected at one station in Tomahawk Lake, the habitat being marshy 
in character. Some pathologic forms occur in the Wisconsin shells, 
the abnormalities being confined principally to the last whorl and aper- 
ture. Specimens from Lake Harriet, Minnesota, collected by Mr. L. 
E. Daniels, are also referable to this race. In the course of time this 
race will probably assume specific characteristics, a fact foretold by 
its remarkable uniformity. 
The race is dedicated to my wife, Mrs. Lillian M. Baker, who 
assisted in the discovery of the type specimens. 
Lymneza stagnalis sancteemarize (Walker). Plate X XI, figures 
1-7; plate XXII, figures 7, 8; plate XXIII, figures 1-3. 
Limnea stagnalis sanctemarie WALKER, Nautilus, VI, p. 31, pl. 1, figs. 4, 5, 
1892; Rev. Moll. Faun. Mich, pp. 7, 17, 1895. 
Lymnea stagnalis var. sanctemarie Wacker, An. Rep. Mich. Geol. Surv., 
1908, p. 289, fig. 63, No. 2, 1909. 
Limnea stagnalis var. sanctemarie@ COocKERELL, Science Gossip, No. 388, 
p. 27, Feb. 1893. ; 
Limnea stagnalis higleyi BAKER, Nautilus, XVIII, p. 142, 1905. 
Lymnea stagnalis var. higleyi WALKER, An. Rep. Mich. Geol. Surv. 1908, 
p. 289, fig. 63, No. 5, 1909.—GLEASoN, |. c., pp. 6-64, 1909. 
Limnea stagnalis var., WALKER & RUTHVEN, Rep. Geol. Surv. Mich., 1905, 
pp. 97, 98, 1906. 
Lymnea stagnalis var., WALKER, An. Rep. Mich. Acad. Sci., 1908, p. 289, 
fig. 63, Nos. 3, 6, 1909. 
Limnea jugularis Sows., Conch. Icon., XVIII, Lim. pl. 4, fig. 24, 1872. 
Limnea stagnalis ApAMs, Rep. Geol. Surv. Mich., 1908, p. 10, 1909. 
SHELL: Broadly ovate, with short spire and widely expanded 
aperture, which is usually twice the length of the spire; spire whorls 
flattened, producing a mammilliform appearance; spire rapidly accu- 
minating ; whorls, 5%; body whorl very large, rounded or even glob- 
ular, slightly shouldered in some specimens; aperture large, somewhat 
flaring, expanded; axis typically strongly gyrate; the umbilical region 
