528 THE CHICAGO ACADEMY OF SCIENCES. 



32-33. Galba intertexta (CURRIER). Black Lake, Holland, Mich., adult 



(23722). 



34-35. Galba catascopium (SAY). Black Lake, Holland, Mich. (23723). 

 Figures 1-5, 11, 12, 32-35, slightly enlarged ; figure 31, enlarged about 2 diameters ; 

 figures 6-10, 13-30, natural size. 



PLATE XLI. 



Figure 1. Galba catascopium (SAY). Delaware River, near Burlington, N. J. 

 (24632). 



2. Galba catascopium (SAY). Delaware River, Philadelphia, Pa., near 



Say's original locality (24616). 



3. Galba pinguis (SAY) ^catascopium (SAY). Delaware River, Phila- 



delphia, Pa. (24616). 



4. Galba pinguis (SAY) =catascopium (SAY). Ohio (23771). 



5. Galba davisi (WALKER). Fish Point, Tuscola Co., Mich. TYPE (Coll. 



Walker, 20092). 

 6-7. Galba pseudopinguis (BAKER). Canarsie, Long Island, N. Y. 



(24535). 



8-9. Galba decollata (MIGHELS). Maine. Bos. Soc. N. H., 24192). 

 10. Galba decollata (MIGHELS). Maine. (Coll. Walker). 

 11-14. Galba sumassi (BAIRD). TYPES in British Museum. 11-12 and 



13-14 back and front view of same specimen. 

 15-17. Galba sumassi (BAIRD). Echo Canyon, Utah (23879). 

 18. Galba emarginata (SAY). Lake Superior (23991). 

 19-20. Galba emarginata (SAY). Mackinac Island, Mich. (23676). 

 21-24. Galba emarginata (SAY). Seneca Lake, N. Y. (23680). 

 25. Galba emarginata mighelsi (BINNEY). Square Lake Inlet, Aroos- 



took Co., Me. (23693). 

 Figures 1-17, enlarged about l l / 2 diameters; figures 18-25, natural size. 



PLATE XLII. 



Figures 1-4. Galba catascopium niagarensis BAKER. Squaw Island, Niagara 



River, N. Y. (23743). 

 5-8. Galba catascopium adamsi BAKER. St. Clair Flats, near Detroit, 



Mich. (TYPES, 23730). 

 9-13. Galba pseudopinguis (BAKER). Crystal Brook, Long Island, N. Y. 



N. Y. (TYPES, 23800). 

 14-17. Galba nasoni (BAKER). Thunder Bay Island, Alpena, Mich. 



(TYPES, 23788). 

 18-20. Galba woodruffi (BAKER). Lake Shore, Oak St., Chicago, Ills. 



(TYPES, 3425). 



21-22. Galba woodruff, (BAKER). Lake Shore, Chicago, Ills. (23791). 

 23-25. Galba decollata (MIGHELS). Maine (Walker Coll., ex Mighels, 



1926). 



26. Galba decollata (MIGHELS). Unity, Maine (23811). 

 27-31. Galba jacksonensis (BAKER). Jackson Lake, Wyoming. (TYPES, 



23806). 

 32-33. Galba gabbii (TRYON). Clear Lake, Cal. (Coll. Hemphill). 



