The shell of
Zemitrella mahoenuica can reach a length of and a diameter of . The shell is moderate sized for the genus. The
spire outline is straight, interrupted somewhat by the slightly incised suture. The
protoconch is smooth, shining and papilliform. The nucleus is depressed. The embryonic lip is thickened where it passes abruptly into the post-embryonic shell. The
sculpture consists of an ill-defined subsutural groove and many (about 13) fine spiral grooves separating threads on the base and neck. The
whorls are otherwise smooth except for faint growth lines. The outer
lip is thickened within and has a prominent denticle a third the distance from the posterior notch. ==Distribution==