Trapezium

(tra-pez' -e-um). In anatomy: I. The first bone of the second row of carpal bones. 2. A tract of the brain consisting of a transverse fiber-ma situated in the ventral part of the oblong at a nearly coinciding with the level of entry of the cephalic acoustic root. Cephalad it extends into the lateral part of the lemniscus. It is probably a part of the centripetal auditory tract. Exposed in most animals, it is in man covered by the caudal extension of the pons.