Figure 57. Geographic distribution of Neosemantis distephanus. N: total number of positive records [total number of samples where the species was presumably sought], for water-column (above 150 m and below 150 m; plankton and sediment trap materials) and surface sediment materials. Sources: A, Petrushevskaya (1971); B, Takahashi (1991); C, Paverd (1995).