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About the Author

Author Info

Dr. Robert T. Dillon, Jr. is America’s foremost authority on freshwater gastropods.  From 1983 until his retirement in 2016 he was Professor of Biology at the College of Charleston in South Carolina.  He is the author of The Ecology of Freshwater Molluscs (Cambridge University Press, 2000) and over 60 scientific papers on the genetics, evolution, and ecology of snails.  A former president of the American Malacological Society, Dr. Dillon wrote the freshwater gastropod chapter for the popular 2006 AMS publication, The Mollusks: A Guide to their Study, Collection and Preservation.  In 1998 he founded the Freshwater Gastropods of North America Project, a long-term, collaborative effort to inventory and monograph the entire gastropod fauna inhabiting every river, lake and stream throughout the continent north of Mexico.  Four volumes have been published in the FWGNA series to date, with three more in preparation.


In his 1977 description of the species, Fred Thompson stated that “Marstonia ogmorhaphe is distinguished from all other species of Marstonia by (1) its large size (4 – 5 mm), and (2) its large number of whorls (5.2 – 5.8).”  Three pages later, he gave the length of the holotype of Marstonia olivacea (Pilsbry 1895) as 4.35 mm, and number of whorls as 5.4.  What gives?  Find out in this month's post to the FWGNA Blog, "Is Marstonia olivacea extinct?"

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