For more information about Lucilla singleyana or land snails in general, feel free to check out my sources.  These included journals, books, and websites. 

Nekola, Jeffrey C.  2003.  Large-scale terrestrial gastropod community composition patterns in the Great Lakes Region of      North America.  Diversity and Distributions Journal 9: 55-71

Miller, Barry B.  1970.  The Sandahl molluscan fauna (Illinoian) from McPherson County, Kansas.  Kent State University, Kent, Ohio, USA.

Baker, Frank Collins.  1939.  Fieldbook of Illinois Land Snails.  Natural History Survey Division, Illinois.  72, 89, 163.

Averell, W.D. and Pilsbry, H. A.  1889-1890.  The Nautilus.  Volume III.  2, 55-57, 115, 125.

Hotopp, K.P., Pearce, T., Nekola, J., Schmidt, K. 2010. New land snail (Gastropoda: Pulmonata) distribution records for New York State. Proceedings of the Philadelphia Academy of Natural Sciences. 159:25-30.

Hubricht, Leslie.  1985.  The Distributions of the Native Land Mollusks of the Eastern United States.  1359.  22, 25. 

Pilsbry, Henry A.  1948.  Land Mollusca of North America (north of Mexico).  Philadelphia, PA.  635-640.

Wisconsin Department of National Resources 2011.  Accessed 22 March 2011.

Encyclopedia of Life2011.  Accessed 22 March 2011.

Discover Life in America 2011.  Accessed 21 March 2011.