194 



WILLEY. 



fully mature in sex, came as a surprise. I am indebted to Dr. Hunts- 

 man for the following hydrographic data relating to "Prince" station 

 6. It will be seen that they throw no fresh light upon the special 

 biological features of the plankton: — 



Notwithstanding the negative evidence afforded by the hydro- 

 graphic determinations, there is still a possibility that the somewhat 

 extraordinary nature of the plankton samples taken off Robbinston 

 at "Prince" station 6 during the winter of 1916-17 can be attributed 

 ultimately to a remote flooding of Arctic water in the Labrador cur- 

 rent from Baffin Bay, acting in conjunction with the Cabot current 

 issuing from the Gulf of St. LawTence and with the tides of the Bay of 

 Fundy. Its proximate causation may have had a more local agency. 

 It is certain that the individuals of C. hypcrboreiis and Mctridia Jonxja 

 were not produced nor would they reproduce where they were found 

 in the estuary of the St. Croix river, although the exuviation from 

 stage V to stage VI may easily have occurred within our waters. If 

 we may judge from their store of oil, they had thriven amazingly 

 during their wanderings and would have had a good chance to avail 

 themselves of reversed currents to regain their spawning area in the 

 north. Failing this, they would presumably perish as stragglers with- 

 out leaving descendants. Not only do they occur in the Baffin Bay 

 region to the west of Greenland, but they attain their largest dimen- 

 sions there (Aurivillius 1896). Both species w^ere taken in the Dol- 

 phin and Union Strait by the Canadian Arctic Expedition. 



In conclusion it cannot be pretended that our knowledge of the 

 great northern currents, which is so essential in connection with 

 fishery problems, is materially advanced by the present contribution. 

 Its chief claim to consideration is the biological interest appertaining 

 to the identification of the rare males of the hyperborean Calanus in 

 comparatively shallow water a little above the forty-fifth parallel of 

 1 atitude. 



