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bulletin: mvseuim of comparative zoology 



densely; but it still remains the most convenient index to the compara- 

 tive abundance of the plankton as a whole, as distinguished from its 

 various individual components. 



The volumes of the quantitative hauls of 1914 (measured as in 

 previous years, 1914a, 1915), are as follows: — 



The stations may be grouped in three classes, rich, with 100 cc. or 

 more; intermediate, with 30 to 100 cc; and barren, with less than 

 30 cc. The horizontal hauls at Stations 10228 and 10258, where no 

 quantitative hauls were made, put them in the "rich" class; while the 

 same test classes, Stations 10233, 10251 and 10260 as intermediate, 

 10220, 10235 and 10261 as barren. On this basis (Fig. 91) the plank- 

 ton under each square meter of the sea surface was rich over a belt 

 running from off the mouth of the Bay of Fundy southwest to Massa- 

 chusetts Bay and the southwestern basin of the Gulf; probably also 

 covering Nantucket Shoals and following the coast as far west as 

 Marthas Vineyard, with other "rich" areas on the northeastern part 

 of Georges Bank, in the Northern Channel, on Brown's Bank, and off 

 Cape Sable. On the other hand it was very scanty (30 cc. or less) 



' No attention is paid here to the coefficient of filtration of the net, which being the same for 

 all hauls, does not effect their comparative value. 



