Figure 44. Geographic distribution of Helotholus histricosa. 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, Radiolaria.org (photo K. Bjørklund); B, Itaki (2009); C, Original.