Encyclopedia of Life 2012.  <URL:>.  Accessed 21 February 2012. 

Pilsbry, H. A.  1930.  Anatomy and Relationship of Some American Helicidae and Polygiridae.  Academy of Natural Sciences82:  303-327.

Wade, C. M., Mordan, P. B., Clarke, B.  2001.  A phylogeny of land snails (Gastropoda:  Pulmonata).  The Royal Society 268:  413-422.

Dourson, D. and Dourson J.  2006.  Land Snails of the Great Smoky Mountains (Eastern Region).  Appalachian Highlands Science Learning Center.   Pages:  5-9, 40.

Pilsbry, H. A.  1940. Land Mollusca of North America (North of Mexico).  Monographs of the Academy of Natural Science of Philadelphia, 1 (part 2):  702-705, 759-760.

Zip Code Zoo 2012. <URL:>.  Accessed 22 March 2012.

Nature Serve 2011. <URL:>.  Accessed 22 March 2012.

Hickman, C. P., Roberts, L. S., Keen, S. L., Larson, A., and Eisenhour, D. J.  2009.  Animal Diversity.  Mc Graw Hill.  Pages:  186-191

If you have any questions or concerns, please feel free to contact us.