1911 Encyclopædia Britannica/Potto

POTTO, the native name of the West African slow-lemurs, popularly miscalled “sloths,” and scientifically known as Perodicticus, a name referring to the aborted condition of the index finger, which forms their most distinctive feature. The ordinary potto (P. potto) is about the size of a squirrel, but with large staring eyes, and a mere stump of a tail; its general colour is rufous brown. Bates's potto (P. batesi), of the Congo, is nearly allied; but the awantibo (P. [Arctocebus] calabarensis), of Old Calabar, differs by the complete loss of the tail (see Primates).