Lewis & Short

portātōrĭus, a, um, adj. [porto], that serves for carrying: sella, a sedan, Cael. Aur. Tard. 1, 1, 15: Christus portatoriis nubibus ascendens, Ambros. Serm. Temp. 180, 1.
As subst.: portātōrĭa, ae, f. (sc. sella), a sedan chair, Cael. Aur. Tard. 2, 13, 161.