Figure 49. Geographic distribution of Larcospira quadrangula. 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, Original; B, Boltovskoy (1999); C, Takahashi (1991); D, Original.