The occasional invasion of Rosenmüller's fossæ by adenoid vegetations, and my inability to remove them thoroughly by any instrument which has come to my notice, without at the same time doing injury to the cartilage of the Eustachian tube, has led me, after examination of cadavers and of the dimensions and position of this fossa, to devise the instrument here described.
A glance at the anatomy of the parts will show the desirability of clearing Rosenmüller's fossa if it is invaded by adenoid tissue. A cross section of the Eustachian tube near its pharyngeal orifice (Fig. 1) shows it to be composed of a cartilaginous and membranous portion. The section of the cartilage is U-shaped, with the opening downward. The posterior medial plate is wider vertically than the antero-external plate. The remainder of the periphery of the tube is the membranous portion, which occupies the greater part of the antero-external