Boll. I'. S. B. I'.. L924. iDoc. 968.) 







Fig. 125. Phytoplankton smith o( Marthas Vineyard, August, 1914 (station 10258), dominated by the 

 diatom Rhizosolenia semisptna. x 150- (Sec list, p. 431.) 



Fig. 126. Midwintei phytoplankton in the inner pari of Massachusetts Bay (station 10488, December, 1920), 

 dominated bj the diatom genus Cosclnodiscus, with < ihaetoceras, the peridinian Ceratitim longipes, and micro- 

 copepods. X 40 



