52G THE CHICAGO ACADEMY OF SCIENCES. 



PLATE XXXVI. 



Figures 1-6. Galba reflexa (Say). Rock Run, Joliet, Ills. (23546). Pathologic 

 forms. 



7-11. Galba crystalensis (Baker). Crystal Lake, Ills. (Types, 23634) 

 =reflexa, immature. 



12. Galba reflexa walkeri (Baker). Calumet River, Ills. (23572). 



13. Galba reftexa walkeri (Baker). Calumet Lake, Ills. (23570). 



14. Galba reflexa walkeri (Baker). Joliet, Ills. (23569). 



15-16. Galba reflexa walkeri (Baker). Wolf Lake, Ills. (23571). 



17. Galba reflexa walkeri (Baker). Silver Lake, Ills. (23527). 



18. Galba reflexa walkeri (Baker). Silver Lake, Ills. (23578). A form 



with spire resembling that of cxilis. 

 19-20. Galba reflexa hemphilliana (Baker). Lake Albert Lea, Minn. 



Types (Coll. Bryant Walker. 14037). 

 21-22. Galba exilis (Lea). Calumet River, Ills. (23577). 

 Figures 11 and 13 are enlarged V/2 diameters; the other figures are about 



natural size. 



PLATE XXXVII. 



Figure 1. Galba exilis (Lea). Berry Lake, Chicago, Ills. (23583). 



2. Galba exilis (Lea). Antrim Co., Mich. (23591). 



3. Galba-cxilis (Lea). Winnebago Co., Ills. (23580). 

 4-6. Galba-exilis (Lea). Mercer Co., Ills. (23582). 

 7-10. Galba exilis (Lea). Des Moines, la. (23585). 



11. Galba exilis (Lea). Des Moines, la. (23595). 



12-13. Galba kirtlandiana (Lea). Crystal Lake, Ills. (23607). 



14-16. Galba kirtlandiana (Lea). Mud Lake, Grand Crossing, Chicago, 



Ills. (23610). 

 17-18. Galba lanceata (Gould). Carp Lake, Emmet Co., Mich. (23593). 

 19-22. Galba lanceata (Gould). Tomahawk Lake, Wis. (23590). 

 23-24. Galba attenuata (Say). Near City of Mexico (Coll. Walker). 

 Figure 4, enlarged about V/ 2 diameters ; figures 1-3, 11-24, slightly enlarged ; 

 figures 5-10, natural size. 



PLATE XXXVII-I. 



Figures 1-2. Galba danielsi (Baker). Lake Maxinkuckee, Ind. (Types, 

 23622). 

 3. Galba danielsi (Baker). Lake Maxinkuckee, Ind. Pathologic speci- 

 men. (Coll. Bartsch). 

 4-8. Galba danielsi (Baker). Lake Maxinkuckee, Ind. (23624). 

 9-11. Galba proximo (Lea). San Francisco, Cal. (23642). 



12. Galba proximo (Lea). San Mateo, Cal. (23641). 



13. Galba calif ornica (Sowerby) = proximo (Lea). Specimen com- 



pared with Sowerby's type in British Museum (Walker coll.). 



14. Galba proximo rowellii (Tryox). San Francisco, Cal. (Coll. Hemp- 



hill). 

 15-1S. Galba proximo rowellii (Tryox). San Francisco, Cal. (23659). 

 Showing variation toward proxima. 



