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bulletin: museum of comparative zoology. 



peared in large numbers off southern Nova Scotia and locally in the 

 center of the Gulf in 1915 (Stations 10309, 10313). 



Elsewhere in the coast water, as well as over the continental slope 

 off Nova Scotia a typical "Ceratimn" plankton prevailed (Fig. 97). 

 But the very scanty catches at the three oceanic stations further west 



Fig. 97. — Microplankton types, July-August 1914; 



3, Ceratium plankton 



1, Mixed Ceratium and diatom 



2, Diatom 



5, Radiolarian 



4, TropiccJ, characterized by Trichodesmium 



(Stations 10218, 10220, 10261) were characterized by the presence 

 of the tropical Alga, Trichodesmium. 



In 1914, as in 1913, the Ceratium plankton consisted chiefly of 

 two species of Ceratium, C. tripos and longipes (Paulsen, 1908). In 

 July the latter was much the more numerous of the two in the Gulf, 

 and off southern Nova Scotia (Stations 10229-10243), while C. tripos 



