38 University of Michigan 



although several iinburned regions were studied. Appears to 

 be especially affected by fire, as it was never found in charred 

 logs, under whose bark small molluscs often escaped exter- 

 mination. 



ZONITID^ 



Zonltoidcs arhorea (Say). Habitats: 27, 37, 38, 39, 40, 

 41 , 45 , 47, 48. By far the most abundant mollusc in the 

 hardwoods and other upland habitats. 



Zonitoides exigna {S\.\m^s,on). Habitat 48. Two specimens. 



Zonitoides milium (Morse). Habitat 41. A single specimen. 



Euconulus chcrsimis polygyratiis (Pilsbry). Habitats: 39, 

 41 , 43. Not as widely distributed as B. fulvus, but numerous 

 locally in hardwoods. 



Euconulus fulvus (Miiller). Habitats: 36, 40, 41 , 46, 47, 48. 



Euconulus sp. ? Habitats: 38, 44; juvenile. 



J^itrca hammonis (Strom). Habitats: 22, 40, 41, 45, 46, 

 47, 48. Most abundant in wet places. 



Vitrca indentata (Say). Habitats: t^J, 39, 48. 



Vitrca rhoadsi Pilsbry. Habitats: 22, 37, 41. 



Vitrca binncyana (Morse). Habitat 46. Cleared swamp. 



Vitrca fcrrca (Morse). Habitat 43; swamp. 



HELICID-?! 



Polygyra albolahris (Say). Habitats: 36, 37, 38, 41. Ii 

 the drier habitats. Small, light and fragile; largest: alt. 17.5 

 mm. ; g. diam. 26.9 mm. 



Polygyra albolahris maritima (Pilsbry). Habitat 38. Abun- 

 dant throughout sandy, outwash plains, but mainly dead shells 

 found, as this region was most affected by the fires. A repre- 

 sentative example: alt. 13.5 mm.; g. diam. 21. i mm. 



Polygyra fratcrna (Say). Habitats: 37, 38, 41. In the 

 drier habitats. An example: alt. 6.8 mm.; g. diam. 11.5 mm. 



