PLANKTON OF THE GULF OF MAINE 



313 



Passamaquoddy Bay closely parallels Massachusetts Bay, for Saggitta; do not appear 

 at all in Doctor McMurrich's plankton lists for St. Andrews between the first week 

 in April and the first week in June. Our spring cruises in 1915 and 1920 suggest 



Fig. 87.— Numbers of Sagitta elegans per square meter of sea area in March, April, and May, as calculated from the vertical 

 hauls. O. 'ess than 50, including stations where none were taken in the verticals; ©, 50 to 400; •, 400 to 1,000; 9 

 1,000+; ■■. stations where the horizontal haul yielded a swarm, but where no vertical haul was made 



that the stock of S. elegans is at its lowest ebb over the inner parts of the gulf as a 

 whole at about the same season (that is, end of April and beginning of May) as it is 

 in Massachusetts and Passamaquoddy Bays (fig. 87) but does not fall to so low an 



