partly by da:a which were kindly supplied by Dr. G. T. Rowe: Several thousand photographs taken from the''Alvin'' along a transect of the Tongue for the amount of seagrass on the bottom were analyzed by P. Polloni and N. Staresinic The total area surveyed was 904 m2, and no less than 11.3 m' or 1.2% of the bottom proved to be covered with a layer of detrital Thalassia. The quantities dredged by the"Pilisbury" and the"Akad. Kur- chatov" are recorded in Table 1