fos's ula

[L. dim. of A fo a, ditch.] i. fo ette, a. small fo a. 2. minor fi ure or slight depre ion on the surface of the cerebrum. £. fenes'trsB coch'leae [BNA], little fo a of the fenestra of the cochlea; a depre ion on the inner wall of the tympanum at the bottom of which is the fenestra rotunda or cochlear window. f. fenes'trae vestib'uli [BNA], little fo a of the fenestra of the vestibule, a depre ion on the inner wall of the tympanum at the bottom of which is the fenestra oval is or vestibular window, [f. petro'sa [B NA], petrosal fo a, a, small and often but faintly marked depre ion on the inferior surface of the petrous portion of the temporal bone, between the jugular fo a and the external carotid foramen; here opens the canaliculus tympanic us transmitting the tympanic nerve.