ARCTIC COPEPODA IN PASSAMAQUODDY BAY. 193 



Euchaeta norvegica IV 1 per cent. 



« " V 56 " 



« « 9 20 " 



« « cT 14 " 



Metridia longa 1 



The high percentage of males of Euchaeta is a proportion not 

 hitherto met with in the free plankton of this region, possibly owing 

 to the fact that bottom-tows, i.e. with the net a little over the bot- 

 tom in deep water, are not usually attempted at our stations. A tow 

 at ten fathoms at an adjacent station ("Prince" station 1) off East- 

 port at the same time (August 2, 1916) yielded 54 cc. of plankton 

 material from which the following Copepod count was made: — 



Calanus finmarchicus II 2 



III 8 



« « IV 17 



« . « V 80 



« « 9 8 



« « cf 22 



" hyperboreus IV 9 



« " " V 8 



« « 9 3 



Pseudocalanus elongatus 50 



Euchaeta norvegica V 5 



" « 9 2 



Metridia longa 12 



lucens 4 



Total counted 230 



The excess of male C. finmarchicus in this gathering has no particu- 

 lar significance because the same station three weeks earlier (July 10th) 

 yielded males and females in equal numbers. The individuals of 

 stage V varied in length from 2.6 to 4.6 mm., and would be continu- 

 ally replenishing the stock of females. 



The mere presence of the three Arctic species (C. hyperborevs, 

 E. norvegica, and M. longa) in Passamaquoddy Bay is not unex- 

 pected but in our experience it is exceptional to find them extending in 

 winter so far up the bay as to penetrate well within the mouth of the 

 St. Croix river. Moreover the association of males and females 

 of C. hyperboreus, although in a nascent state, adult in form but not 



