514 THE CHICAGO ACADEMY OF SCIENCES. 



E; Galba obrussa (SAY). C, central tooth; 1, 2, 7, lateral teeth; 9, 

 transition tooth ; 11, 13, first marginals ; 15, 16, 21, typical mar- 

 ginals. 



P. Galba cubensis (PFR.). C, central tooth; 1, 3, lateral teeth; 7, inter- 

 mediate tooth; 9, 13, 21, 22, marginal teeth. 



PLATE VIII. 



RADUL^E. 



Figure A. Galba umbilicata (ADAMS). C, central tooth; 1, first lateral tooth; 

 3, third lateral; 5, intermediate tooth; 7, 8, 9, marginal teeth. 



B. Galba umbilicata (ADAMS). Seventh tooth (marginal) in one mem- 



brane. 



C. Galba obrussa exigua (LEA). 1, 3, 6, lateral teeth; 7, intermediate 



tooth; 8, 9, true marginal teeth. 



D. Galba obrussa exigua (LEA). Variation in first marginal on different 



membranes. 



E. Acella haldemani ((DESK.) BINNEY). C, central tooth; 1, 2, 7, lat- 



eral teeth; 9, intermediate tooth; 10, 11, 16, marginal teeth. 



F. Galba palustris (MULLER). C, central tooth; 1, 2, lateral teeth; 10, 12, 



intermediate teeth; 14, 16, 17, 18, marginal teeth. 



G. Galba elodes jolietensis (BAKER). 1, lateral tooth; 9, 10, intermedi- 



ate teeth; 11, 13, 16, marginal teeth. 

 H. Galba palustris (MULLER). First lateral tooth, with a split or bifed 



ectocone. 

 I. Galba palustris desidiosa (SAY). 1, first lateral; 10, 11, intermediate 



teeth; 14, 19, marginal teeth. 

 J. Galba bulimoides cockerelli (PiLS. & FERR.). 8, 10, intermediate 



teeth; 11, first marginal tooth. 



PLATE IX. 



RADUL^E. 



-Figure A. Galba reflexa (SAY). <C, central tooth; 1, first lateral tooth; 12, last 

 lateral tooth; 14, transition tooth; 18, first marginal; 20, 21, 22, 

 typical marginals. 



B. Galba danielsi (BAKER). C, central tooth; 1, 8, lateral teeth; 10-11, 



intermediate teeth ; 12, 13, 25, marginal teeth. 



C. Galba danielsi (BAKER). Tenth tooth (intermediate) in one speci- 



men. 



D. Galba emarginata (SAY). C, central tooth; i, 10, first and tenth 



lateral teeth; 11, 12, intermediate teeth; 13, 15, marginal teeth. 



F. Galba emarginata (SAY). Thirteenth tooth (marginal in one speci- 



men). 



G. Galba emarginata mighelsi (BINNEY). 1, first lateral tooth; 12, 13, 



transition teeth; 17, 22, marginal teeth. 

 H. Galba emarginata angulata (Sowe.). 11, 12, intermediate teeth; 13, 



marginal tooth. 

 I. Galba catascopium (SAY). C, central tooth; 1, first lateral; 10, 11, 13, 



transition teeth; 14, 15, 26, 27, marginal teeth. 

 J. Galba caperata (SAY). C, central tooth; 1, first lateral; 9, 10, 12, 



intermediate teeth; 14, 15, 24, 28, marginal teeth. 



