LYMNAIDZ OF NORTH AMERICA. 519 
PLATE XXI. 
Figure 1. Lymnea stagnalis higleyi BAKER. Michipicoten Island, Lake Superior. 
TYPE (23050). 
2. Lymnea stagnalis higleyi Baker. Michipicoten Island, Lake Superior. 
(23052). 
3. Lymnea stagnalis higleyi BAKER. Michipicoten Island, Lake Superior. 
CotyPe (Coll. Ferriss). 
4-5. Lymnea stagnalis sanctemarie Waker. Siskowit Lake, Isle Roy- 
ale, Mich. (23927). 
6-7. Lymnea_ stagnalis sanctemarie WALKER. Specimens showing 
thickening of columella by callus, thus obscuring the gyrate 
character of the axis. Figure 7 shows the formation of the 
callus, while figure 6 shows the typical condition. The latter is 
a younger shell. (23926.) 
8-9. Lymnea stagnalis lilliane Barer. Lake Harriett, Minneapolis, 
Minn. (23049). 
10-12. Lymnea stagnalis lilliane BaKxer. Tomahawk Lake, Wisconsin. 
Types (24554). 
Figures 4 to 7, slightly reduced; figure 2, enlarged; balance natural size. 
PLATE XXII. 
Figures 1-2. Lymnea stagnalis appressa Say. Nautilus, VI, pl. 1, figs. 2-3. 
% nat. diam. 
3. Lymnea stagnalis appressa Say. Distortion. Nautilus, VI, pl. 4, fig. 
1. % nat. diam. 
4. Lymnaea stagnalis appressa Say. Variety. Dredged from depth of 10 
meters in Lake Michigan, at High Island Harbor, Beaver 
Island. (Photo by Walker.) 
5. Lymnea stagnalis perampla WALKER. Nautilus, VI, pl. 1, fig. 6. % 
nat. diam. 
6. Lymnea stagnalis liliane Baker. Minnehaha River, Minn. (Coll. 
Hemphill). 
7-8. Lymnea stagnalis sanctemarie WALKER. Types. Nautilus, VI, 
pl. 1, figs. 4-5. % nat. diam. 
9-11. Galba utahensis (Catt). Bull. U. S. Geol. Surv., II, pl. 6, figs. 
7-9 (x2). 
12-15. Radix auricularia (LinNE). Greenhouse, Lincoln Park, Chicago 
(23087). Slightly enlarged. 
PLATE XXIII. 
Figures 1-3. Lymnea stagnalis sanctemarie WALKER. Sault Ste. Marie, Mich. 
(23051). 
4-5. \Lymne@a stagnalis occidentalis Hempuitt. Lake Whatcom, Wash- 
ington. Types (Coll. Hemphill). 
6-7. Lymnea lepida GouLtp. Tryon’s Continuation Haldeman’s Mono- 
graph, pl. 16, figs. 12-13. 
8. Pseudosuccinea columella (Say). Pennsylvania (23061). 
9. Pseudosuccinea columella (Say). Greenwood, S. C. (23060). 
10-12. Pseudosuccinea columella (Say). Bradford, Conn. (23063). Figure 
11 is a typical macrostoma Say. 
