CAXADIAX Flf^HERIES EXPEDITIoy, lOl'rlo 



177 



habit. The records indicate that the Galanus inhaibiting these waters is part of one 

 vast, continuous community, whose southern frontier is not a straight parallel of lati- 

 tude but a scalloped border which changes with the seasons; but it is none the less a 

 definite boundary because the species holds together in virtue of the cohesion of the 

 individuals. The Calani, with their rich oily bodies, form a floating mass which does 

 not readily mix with the pure Atlantic water; the line of separation of the calanife- 

 rous water from the oceanic water is like a line of contact between fluids of different 

 viscosity which have a slight tendency to mix ; the degree of viscosity being influenced 

 by the presence of the copepod swarm. 



Calanus finmarchicus is both euryhaline and eurythermal, i.e. it is independent of 

 ordinary diurnal and seasonal fluctuations of temperature and salinity. This fact is 

 brought out very clearly by the records of No. 33 station 23, which show a gradation 

 in percentages of this species entirely disconnected with the gradations in temperature 

 and salinity. 



Table C. — Steam Trawler No. 33, station 23, June 25, 1915, between Anticosti and 

 Gaspe; 49° 31' K, 63° 58' W.; depth 855 metres. 



The tables (I-XII) accompanying this report display the distribution of the prin- 

 cipal species met with. It is not necessary to continue the tabulation of every station 

 from Acadia 57 to 90, and I will therefore deal with this portion of the exploration 

 somewhat more summarily. 



Table D. — Percentage of C. finmarchicus of all ages at Acadia stations 57 to 67. 



