478 



DEPARTMENT OF THE yiVAL SERVICE 



only two where deep hauls were made. On the later cruises the centre of abundance 

 (as shown by the closely placed lines in fig. 12) was definitely in the northern oceanic 

 water just south of the Newfoundland banks. It decreased in quantity to the north. 



Fig. 12. — Distribution of E. hamata, July- August 1915. Zones showing frequencies of 1 to 20, 21 to 75 



and 75 and over per station. 



west, and south. The agreement with the distribution of S. maxima is very evident. 

 They both belong to the deeper part of the boreal oceanic water and show its extension 

 up the Laurentian channel and to the south along the outer side of the continental 

 shelf and to some extent over the banks, but diminishing in amount in each direction. 

 The two species differ in that S. m,axima can not endure as much of a decrease in 

 salinity as can HJ. hamata, and does not extend as far up the Laurentian channel or 

 over the banks as the latter species. It can, however, endure an increase in salinity 

 better than E. hamata, as it occurs in the outer Gulf Stream stations, where the latter 

 is absent on the later cruise though present on the earlier. High temperature may, 

 however, be as potent a factor in excluding E. hamata from the Gulf Stream as high 

 salinity. 



