PLANKTON OF THE GULF OF MAINE 



157 



the summer of 1915" (Bigelow, 1917, p. 286), as well as over the southwest part of 

 Georges Bank in July, 1916 (stations 10351 and 10353), which substantiates the 

 tow nettings made by vessels of the Bureau of Fisheries in past years. 



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J 



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Flo. 55. — Occurrence of the ampnipod genus Euthemisto, July, August, and the first week of September. •, locality 

 records for E. compressa; O, locality records for E. bispinosa; Q, locality records for both species together. The large 

 symbols are for the more notable swarms 



This zone of abundance can hardly extend out beyond the continental edge, 

 for, generally speaking, we have found Euthemisto decidedly less common over the 

 continental slope and rare at the deep stations where the plankton is characterized 



