N. nivea. Three syntypes in (he B.M.N.H.; illustrated syntype 23.3 X 12.9 X 11.5 mm. White in colour, sculptured with 13 axial ribs and 10 spiral cords on the penultimate and 18 ribs and 20 cords on the body whorl, columella with 2-3 plicae anteriorly and a parietal fold with 2 adjoining denticles, outer lip with 15 plicae. Batangas, island of Luzon, Philippines, 21 fathoms (38 m) = error.
N. plicatella. Two syntypes in ihe B.M.N.H.; illustrated syntype 24.4 X 13.7 x 11.8 mm. Creamy-white in colour, early whorls brownish, sculptured with 14 axial ribs and 8 overriding spiral cords on the penultimate and 11 ribs and 20 cords on the body whorl, axial ribs indistinct on back of dorsum, columella with a basal and a parietal fold with 2 adjoining denticles, outer lip with 13 plicae. Walvis Bay, Africa [= Walvis Bay, S.W. Africa].