518 THE CHICAGO ACADEMY OF SCIENCES. 



11. Lymncea maxima Stearns. Univ. Cal. Pub., Geol., V, p. 69, fig. 1. 



Type. 



12. Lymncea contracosta J. G. Cooper. Proc. Cal. Acad. Sci., ii, IV, pi. 



14, fig. 12. Type. 



13. Lymncea scudderi Cockerei.l. Bull. Am. Mus. N. H., XXII, p. 461, 



fig. 4, a. Type; b, narrow variety of scudderi; x 4^2. 



14. Lymncea sieverti Cockerell. L. c, fig. 3. Showing interior of shell 



and outside of a portion near the mouth ; X 4. 



PLATE XVIII. 

 Section of shells to show axis. 

 Figure 1. Acella haldemani ('Desh.' Binney). 23936. 



2. Galba bulimoides cockerelli (Pils. & Ferr.). 23940. 



3. Galba obrussa (Say). 24506. 



4. Galba palustris (Muller). 23987. 



5. Pseudosuccinea columella (Say). 23931. 



6. Galba randolphi (Baker). 23675. Young. 



7. Lymncea stagnalis appressa Say. 23925. 



8. Bulimnea megasoma (Say). 23097. 



9. Radix auricularia (Linne). 23934. 

 10. Galba reflexa (Say). 23988. 



Figures Enlarged. 



PLATE XIX. 



Figures 1, 2. Lymncea stagnalis Linne. Baden, Germany (23008). 



3. Lymncea stagnalis Linne. Elba River, Germany (Coll. Walker). 



4. Lymncea stagnalis appressa Say. Braddocks Bay, Lake Ontario, N. 



Y. (23035). 

 5-6. Lymncea stagnalis appressa Say. Round Bay, Lake Ontario, N. Y. 

 (23006). 



7. Lymncea stagnalis appressa Say. Calumet Lake, Ills. (Coll. Ferriss). 



8. Lymncea stagnalis appressa Say. Pigeon Lake, Ontario (23046). 



9. Lymncea stagnalis appressa Say. Calumet River, Ills. (8113). 

 10. Lymncea stagnalis appressa Say. Romeo, Ills. (23009). 



Figures Natural Size. 



PLATE XX. 



Figures 1, 2, 3. Lymncea stagnalis appressa Say. Squaw Island, Niagara River, 

 N. Y. (Coll. Walker). 



4. Lymncea stagnalis appressa Say. Calumet Lake near Pullman, Ills. 



(19584). 



5. Lymncea stagnalis appressa Say. Bear Lake, Mich. (23014). 



6. Lymncea stagnalis appressa Say. Batavia, N. Y. (23015). 



7. Lymncea stagnalis perampla Walker. Houghton Lake, Mich. Co- 



type (23924). 



8. 9. Lymncea stagnalis perampla Walker. Douglas Lake, Mich. (Coll. 



Ferriss). 

 10-12. Lymncea stagnalis wasatchensis Hemphill. Near Ogden, Utah. 

 Types (Coll. Hemphill). 

 Figure 6, enlarged 1 1/3 ; figure 5, enlarged 2 diameters ; balance natural size. 



