Amnicola bithynoides Yen, 1944 † (original description)
Angulorbis Yen, 1944 † accepted as Idahoella Yen, 1948 † (original description)
Angulorbis multicarinatus Yen, 1944 † accepted as Idahoella multicarinata (Yen, 1944) † (original description)
Fluminicola weaveri Yen, 1944 † (original description)
Goniobasis taylori (Gabb, 1866) † (basis of record)
Melania decursa Conrad, 1871 † accepted as Goniobasis taylori (Gabb, 1866) † (additional source)
Orygoceras tricarinatum Yen, 1944 † accepted as Orygoceras (Ibicicornu) arcuatum Dall, 1924 † accepted as Orygoceras arcuatum Dall, 1924 † (original description)
Payettia dallii (C. A. White, 1882) † (basis of record)
Pilsbryus Yen, 1944 † (original description)
Pilsbryus antiquus (Gabb, 1866) † accepted as Pilsbryus occidentalis (J. Hall, 1845) † (basis of record)
Pilsbryus superbus Yen, 1944 † (original description)
Pisidium exiguum Yen, 1944 † accepted as Pisidium woodringi Yen, 1945 † (original description)
Pliopholyx Yen, 1944 † (original description)
Pliopholyx idahoensis Yen, 1944 † (original description)
Pyrgulopsis carinata Yen, 1944 † (original description)