BIGELOW: EXPLORATIONS OF THE COAST WATERS. 



293 



to be overlooked, was detected at only four stations in 1915 (Stations 

 10303, 10307, 1030S, 10314), instead of being widely distributed as in 

 former years (p. 295). On the other hand the 1915 hauls add one 

 species, Eiicalanus clongatus, to the list of the Gulf of Maine cope- 

 pods (Station 10253), interesting because it is a typical warm water, 

 oceanic form (Farran, 1911), not previously recorded from the general 

 region. The records of Rhincalanus 7iasidus (Station 10272, 10273), 

 Eiichcirclla rostrata (p. 246, Stations 10270, 10294, 10310) and PJeuro- 

 mamma ahdomlnalis in the Gulf (p. 246) are likewise worth noting, 

 because of their oceanic origin. 



-■^•W) 



Fig. 88. — Locality records for Euchaela nonegica in the Gulf of Maine and off Nova 

 Scotia, 1912-1915. 



Copepods practically disappear from the western side of the Gulf in 

 April (1914b). But very little is known of the manner of their reap- 

 pearance, i. e., whether the copepod fauna is reestablished, more or less 

 evenly over the Gulf, by the multiplication of the few which survive 

 during the barren season ; or whether it is recruited from local centers 

 of reproduction, or by migration from outside w^aters. The great 

 regional variation in number of copepods in May (p. 314), and the 

 subsequent equalization which takes place during the summer, shows 

 that in 1915 at least there were two distinct centers for copepods in 

 spring, one on the western, the other on the eastern side of the Gulf; 



