284 



Birge — T7ie Crustacea of the Plankton. 



Table II. — Showing the number of Cyclops caught by the net at the 

 same date and place in a series of six hauls of 3 m. each, and in a 

 single haul of 18 m. 



Date. 



1895. 



Jan. 6 



Jan. 9 



Jan. 16 



Feb. 15 



Feb. 23 



Mch.6 



Mch. 7 



Mch.12 



Mch. 23 



Apr. 12 



Apr. 15 



Apr. 18 



Apr. 23 



Apr. 30 



May 4 



May 7 



May 12 



Sum of 

 series . 



Single 

 haul. 



400 

 378 

 505 



870 



2,350 



345 



678 

 719 



780 

 690 



1,000 

 2,520 

 2,925 

 9,055 



15,470 

 13,630 

 11,980 



460 



550 



600 



800 



1,220 



900 



1,180 



1,430 



620 



859 



844 



1,355 



710 



880 



600 



1,290 



3,550 



9,510 



6,960 



7,620 



5,250 



15,450 



18,200 



19,680 



Date. 



1895. 



May 16 



May 18 



May 20 



May 22 



May 27 



May 30 



June 1 



June 3 



June 10 



June 12 



June 17 



June 18 



June 22 



June 24 



June 29 



July 1 



July 4 



July 6 



July 9 



July 11 



July 19 



July 24 



Sum of 

 series. 



11,940 



19,470 



11,780 



12,850 



16,710 



16,220 



13,220 



10,010 



8,020 



8,070 



4,530 



3,809 



4,760 

 3,710 

 3,299 

 3,190 



3,920 

 6,105 

 3,416 

 2,960 

 3,434 

 2,791 



Single 

 haul. 



14,300 



17,530 



19,200 



16,000 



11,240 



15,625 



17,900 



15,200 



10,080 



7,800 



3 610 



5,600 



3,240 



5,680 



3,750 



2,120 



2,400 



3,700 



3,600 



3,300 



3,960 



2,560 



3.0S0 



3,120 



1,840 



of July. The comparisons of net and tube show no appreciable 

 difference in coefficient between the catches of October when the 

 vegetable plankton is at its maximum, and those of February 

 and May, when it is greatly reduced in quantity. There is 

 therefore no reason to suppose that the coefficient of the dredge 

 is appreciably altered by being raised through the distance 

 of three meters. It may be added that results similar to those 

 obtained in the above table would be shown if any other species 



