Lewis Short
(adjective) : nătātĭlis, e, id.
* That can swim (post-class.): animae,Tert. adv. Herm. 33. —Subst.: nătātĭles, ĭum, m., swimming creatures: feras, volucres, reptiles, natatiles, Prud. στεφ. 10, 332; App. de Mund. 28.
Charlton T. Lewis, Charles Short, A Latin Dictionary