Cope described a fragment of the lower jaw of a small carnivore from the "Loup Fork of Cottonwood Creek, Oregon," as Lutrictis ? lycopotamicus (1879, p. 67). The type has been lost, but was figured (Cope - Matthew, 1915, pl. 119c, figs. 5 and 5a). Matthew (1904, p. 254) corrected the generic reference to Potamotherium (as Cope himself also had done at the time the plate was prepared), and noted the loss of the type and absence of other specimens. He considered it a small species and later (1915, loc. cit.) suggested that it was related to Sthenictis. Also, in 1915, he gave the locality as Pawnee Creek, Colorado, a lapsus calami. In 1922 Thorpe referred two specimens in the Yale Peabody Museum collections to this species. Although these are from the Niobrara River fauna of Nebraska, they may well contain the key to the identity of the Oregon form.