178 



BULLETIN OF THE BUREAU OF FISHERIES 



During April it became so scarce in the Massachusetts Bay region and over the 

 northwestern part of the gulf generally that it did not appear there in the catches 

 of the vertical nets, although the surface tows picked up a few at the localities marked 



Fig. 60.— Occurrence of the copepod Acarlia longiremis, February to April, 1920, surface and vertical hauls combined. 

 X, present; O. not found. The hatched curve incloses the areas where it occurred at every station 



on the chart (fig. 61); but, by contrast, it had spread generally over the whole eastern 

 side of the gulf, with a rather definite line of demarcation between the areas where it 

 did and did no t occur in sufficient number for the vertical net to take it (fig. 61), but 



