SEA-FISHERIES LABORATORY. 283 
distribution of the separate genera or even species 
throughout the year. The Diatoms and the Copepoda 
are certainly such groups, as we have in each case 
abundant evidence that different representatives of the 
eroup flourish best at different seasons. Jonsequently 
we have now picked out from the Diatom records the 
detailed occurrence of the five leading genera, Biddulphia, 
Chaetoceros, Coscinodiscus, Rhizosolenia and Thalassiosira, 
with the results given in the following lists : — 
Bay Dtatoms, 1n 1908, BELONGING TO THE FIVE GENERA. 
Biddul- Chaeto- Coscino- Rhizo- Thalas- 
Date. phia. ceros. discus. solenia., siosira. 
Jan. 4... 2,000 1,700 2,150 ) 0 
7) ple GRERE 3,850 1,500 2,100 0 0 
va elas 4. 6,700 225 4,375 i) ) 
Beh CLO ai 7,500 1,050 2,725 0 0 
Feb. 4 ... 10,000 750 4,800 0 0 
J) Oe 15,3500 1,625 6,800 0 0 
ALO s0 1,300 200 2,300 0 ) 
PS cx 9,000 800 5,600 0 0 
5 bee 15,000 1,500 22,250 () 0 
Mar. 4... 24,500 700 6,800 i) i) 
cae 8,000 150 5,000 75 0 
9 Sa ey aa 50,000 12,000 65,000 0 0 
He ae 52,000 9,200 33,000 0 ) 
Amr, 2... 14,000 6,250 25,000 ) 0 
SY a ee 33,000 10,250 21,500 ) 0 
4 US ie 145,000 48,000 119,700 4,700 2,000 
kbd 1 Se 115,000 40,100 120,000 6,000 14,000 
kG... 155,000 73,750 34,500 0 0 
WM de sa 73,500 62,000 19,750 0 500 
PA ES: oe 100,000 61,000 88,000 2,000 2,500 
Rae. «ss 71,000 51,000 85,000 1,000 1,300 
3g) ZU 45,000 248,000 59,000 0 2,000 
} 7 ae 47,500 129,000 53,000 500 0 
eee |. 25,500 128,500 52,000 1,000 500 
311) 7A ghee 26,000 113,000 51,000 500 0 
oft 74 ie 31,000 261,000 46,000 500 250 
MOOS v5. 47,000 217,125 54,000 1,250 3,500 
at ee 25,000 354,000 27,000 750 ~—- 1,000 
4. aly 25,000 282,750 47,000 500 ~=—:1,500 
Ste) 2: 45,500 302,750 14,500 250 ~=8,000 
RON se 53,000 730,000 40,000 — 3,000 2,000 
Bpr nor. Js: 46,000 873,500 35,500 2,500 ‘1,000 
rae ae 41,000 435,000 26,000 3,500 3,000 
Bb DAL vn 45,000 608,000 27,500 3,500 4,000 
ON «ac 78,025 584,625 9,625 5,000 2,000 
POF ais 46,000 836,000 5,400 8,000 0 
a hens 44,000 816,000 6,500 7,500 0 
