200 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY- 



It may be noted here that in 1911 the hours of 

 sunshine reached the monthly maximum in May, and 

 the total number was considerably greater than that of 

 1910. (See below under Sunshine.) 



If now we neglect the vertical hauls — which are not 

 directly comparable with the horizontal — and treat each 

 pair of coarse and fine net samples taken at the same time 

 as forming together a single double haul, we get the 

 following result for the twelve months : — 



Double Average Diatoms. Dinoflag- Copepoda. Copepod Copepod 

 1911. hauls, catch. ellates. juv. nauplii. 



January 9 3-6 52,064 3,511 3,314 188 1,553 



February ... 6 4-0 60,528 2,508 2,579 222 2,537 



March 10 4-4 245,851 2,495 1,013 175 3,062 



April 11 9-0 240,446 901 2,752 246 3,520 



May 9 460 24,201,900 26,230 9,187 2,039 15,240 



June 11 37-3 3,767,835 50,365 25,285 1,762 44,820 



July 9 18-8 8,209 18,967 75,533 1,229 62,618 



August 8 11-4 1,998 1,510 61,351 2,426 35,058 



September ... 9 15-3 928,501 8,818 31,651 2,426 44,244 



October 8 14-5 4,742,791 10,510 18,559 1,700 32,058 



November ... 8 5-5 506,729 6,574 20,741 894 8,058 



December ... 9 3-4 124,144 5,131 10,492 124 5,190 



This table serves for comparison with those we have 

 published for 1909 in Part III, p. 212, and for 1910 in 

 Part IV, p. 199 ; and shows very clearly the average 

 monthly catches, forming a simple curve rising steadily 

 from 3'6 c.c. in January to 46 c.c. in May, and then 

 declining to 34 c.c. in December. It also shows the two 

 maxima in the Diatom column, the first in May with over 

 24 millions and the second in October with nearly 5 

 millions. Finally the succession of maxima, Diatoms in 

 May, Dinonagellates in June, and Copepods in July, is 

 clearly seen. These maxima are all large ones, in the 

 case of Diatoms and Copepoda much larger than in the 

 previous two years, and in the case of the Dinonagellates 

 only exceeded by that of 1910. 



If we add together Diatoms and Dinoflagellates in 



