QO 



Cincinnati Society of Natural History. 



7. Mesodon thyroides, Say. 



Resembles No. 6, but umbilicus partly covered. Everywhere 

 abundant. 



8. Mesodon multilineata, Lea. 



Beautifully marked with brown longitudinal lines. Woods near 

 river banks. 



9. Mesodon elevata, Say. 



White, spire elevated, large tooth on parietal wall. Wooded 

 hillsides. 



10. Mesodon profunda, Say. 



Brown stripes, open umbilicus, tooth-like projection on outer lip 



near base. Woods. 

 Width of 11, 12, 13 about one-half inch. 



11. Mesodon pennsylvanica, Green. 



Brown, outer lip elongated. In sedge and thicket. 



12. Mesodon mitchelliana, Lea. 



W T hite, umbilicus covered. River bottoms. 



13. Mesodon clausa, Say. 



White, umbilicus partly covered. River bottoms. 



Genus Triodopsis. 



Distinguished by the three teeth, one on body or parietal wall, 



and two on outer lip or peristome. 

 Width of 14, 15, 16, 17, 18 about three-quarters of an inch. 



14. Triodopsis palliata, Say. 15. 



Dark, hirsute, two teeth on outer lip, one long tooth on parietal 

 wall. Under logs. 



15. Triodopsis appressa, Say. 



Smaller than No. 14 and not hirsuite. Stone walls. 



16. Triodopsis tridentata, Say. Rock variety. 17. 

 White. Rocky places. 



17. Triodopsis tridentata, Say. Woods variety. 

 Brown and smaller than No. 16. Woods. 



18. Triodopsis fallax, Say, 19. 



Two teeth on outer lip turn inward. Wooded hillsides. 



19. Triodopsis inflecta, Say. 



Half size of No. 18, umbilicus covered. Wooded hillsides. 



