Aplexa hypnorum var. tryoni (Currier, 1867) accepted as Sibirenauta elongata (Say, 1821) (basis of record)
Euconulus fulvus (O. F. Müller, 1774) (additional source)
Limax montanus Ingersoll, 1875 accepted as Deroceras laeve (O. F. Müller, 1774) (additional source)
Limnaea emarginata (Say, 1821) accepted as Ladislavella emarginata (Say, 1821) (basis of record)
Limnaea emarginata var. montana Elrod, 1902 accepted as Ladislavella elrodiana (F. C. Baker, 1935) (original description)
Limnaea nuttaliana I. Lea, 1841 accepted as Ladislavella elodes (Say, 1821) (additional source)
Limnaea palustris (O. F. Müller, 1774) accepted as Stagnicola palustris (O. F. Müller, 1774) (additional source)
Limnaea stagnalis var. appressa (Say, 1821) accepted as Lymnaea stagnalis appressa (Say, 1821) accepted as Lymnaea appressa (Say, 1821) (basis of record)
Physa ampullacea A. Gould, 1865 accepted as Physella gyrina (Say, 1821) (additional source)
Physa gyrina Say, 1821 accepted as Physella gyrina (Say, 1821) (additional source)
Physa heterostropha (Say, 1817) accepted as Physella acuta (Draparnaud, 1805) (additional source)
Planorbis parvus Say, 1817 accepted as Gyraulus parvus (Say, 1817) (additional source)
Planorbis trivolvis Say, 1817 accepted as Planorbella trivolvis (Say, 1817) (additional source)
Polygyra devia hemphilli (W. G. Binney, 1886) accepted as Cryptomastix mullani hemphilli (W. G. Binney, 1886) (basis of record)
Polygyra townsendiana var. ptychophora (A. D. Brown, 1870) accepted as Allogona ptychophora (A. D. Brown, 1870) (basis of record)
Pyramidula elrodi Pilsbry, 1900 accepted as Oreohelix elrodi (Pilsbry, 1900) (additional source)
Pyramidula striatella (J. G. Anthony, 1840) accepted as Discus whitneyi (Newcomb, 1864) (additional source)
Sphaerium partumeium (Say, 1822) (additional source)
Succinea nuttalliana I. Lea, 1841 accepted as Oxyloma nuttalliana (I. Lea, 1841) accepted as Oxyloma nuttallianum (I. Lea, 1841) (additional source)
Zonitoides arboreus (Say, 1817) (additional source)