Zool. [Brazilian of the Island of Maranhão.] The South American two-toed sloth, Cholopus didactylus.
Adopted by Buffon from C. d’Abbeville Mission des Pères Capucins, etc. (1614), 252. Of the two kinds there mentioned by the names of Unaū and Unaū ouassou the former is Buffon’s Ai, the latter his Unau.
1774. Goldsm., Nat. Hist., IV. xxii. 343. Of the sloth there are two different kinds,… the one, which in its native country is called the unan [sic], having only two claws upon each foot.
1834. H. M’Murtrie, Cuvier’s Anim. Kingd., 93. Only one species [of Bradypus] is known, the Unau…, less uniform in its organisation than the Aī.
1872. Humphry, Myology, 21. A recess and dimple in the astragalus of Unau and of Aī.
