ARCTIC COPEPODA IN PASSAMAQUODDY BAY. 191 



the Due d 'Orleans in the Greenland Sea (1905), Damas and Koefoed 

 reported that the samples from stations 46, 47 and 48 were remarkable 

 for the abundance of eggs and nauplii of C. Juipcrborcus, together with 

 females whose o\aducts were full of eggs, as well as some males which 

 are elsewhere so rare. The following are the positions of the stations 

 in questions: — 

 Station 46. Lat. 77° 29' N., Long. 18° 31' \V. 



Depth 265 metres; vertical haul 13-0 m.; Aug. 4, 1905. 



Eggs and nauplii of C. hypcrborcus in great quantity. 

 Station 47. Lat. 76° 47' N., Long. 15° 21' W. 



Depth 180 metres; vertical haul 20-0 m.; Aug. 8, 1905.. 



Nauplii of C. hyperboreus in great quantity. 

 Station 48. Lat. 71° 22'.5 N., Long. 18° 58' W. 



Depth 1130 metres; vertical haul 10-0 m.; Aug. 15, 1905. 



Oviducts full of eggs; nauplii in great quantity. 



It follows from Damas' researches that the two species, C. fimnarchi- 

 cus and C. hyperboreus reproduce principally at two extreme points of 

 the basin of the Arctic Ocean, the former in the south, the latter in 

 the north. Whilst they are often mixed in planktonic samples, the 

 conditions of their reproduction are quite different. 



From the February material of "Prince" station 6 (1917), I picked 

 out 31 examples of C. hyperboreus distributed as follows: — 



C. hyperboreus IV 6 



V 14 



" 9 5 (7.25 mm. long) 



" & 6 (6.1 mm. long) 



The adults of both sexes were new, transparent, freshly exuviated and 

 turgid with pink oil. Whereas the many males of C. finmarchicus 

 averaged a little over 3 mm. in length, the male C. hyperboreus some- 

 what exceeded 6 mm. and were proportionately bulky so that the 

 contrast in size was most striking. The lateral corners of the last 

 thoracic segment (th 5) of these new males was nearly rounded, at 

 most very obtusely pointed, less pointed that it sometimes appears 

 as a variation in C. finmarehicus, but the spinous armature of the 

 outer branch of the left fifth foot and the coxal teeth of the fifth feet, 

 together with the large size, proved beyond question that they were 

 the males of C. hyperboreus. The large females which accompanied 

 . the males and were equally new and oily, showed the specific point 

 at the lateral edge of th 5; and the coxal teeth of their fifth pair of 

 feet were likewise those of C. hyperboreus. 



