Lewis & Short

mantĭca, ae, f. [manus], a bag for the hand, wallet, cloak-bag, portmanteau: mantica cui (mulo) lumbos onere ulceret, Hor. S. 1, 6, 104: umero exuere, to take off from the shoulder, App. M. 1, p. 110, 27.
Prov.: non videmus, manticae quid in tergo est, i. e. do not learn to know ourselves, Cat. 22, 21 (acc. to the fable, Phaedr. 4, 10, 1); cf.: ut nemo in sese temptat descendere, nemo, sed praecedenti spectatur mantica tergo, Pers. 4, 24 Gildersleeve ad loc.