N. sesarma. Two syntypes in the MCML; illustrated larger syntype 13.0. X 6.7 X 6.0 mm, smaller syntype 10.0 X 5.5 X 5.0 mm. Pale grey in colour with brownish spots especially at the sutures and a few white spots on the body whorl, columella stained brown, shell with 4 mature and 3 nuclear whorls, first post-nuclear whorl with 7 spiral rows of minute pits, next 2 whorls with 2-3 sutural threads, body whorl with c. 29 close-set, fine spiral striae, columella with a basal fold and adjoining denticle, outer lip with 14-15 fine denticles. Whydah [= Ouidah, Dahomey, W. Africa].
N. sesarma is not at all conspecific with N. marratii (E. A. Smith, 1876) [= N. gaudiosus Hinds, 1844] from the Solomon Islands as suggested by Tomlin (1940). Marrat's West African locality is correct and N. sesarma is considered to be a valid species (Prof. W. Adam, in litt.).