MARINE BIOLOGICAL STATION AT PORT ERIN. 65 
of September (fig. 17), due in the main to the great 
abundance of Rhizosolenia semispina, while in 1908 the 
catches remained small and of the usual summer type 
until far on into October. It is only on October 15th 
and 16th that we notice any marked increase in the 
number of Diatoms in the gatherings, and even then it is 
not comparable with the phenomenon of the previous 
autumn. The Diatom Thalassiosira nordenskioldi, which 
BREE 
oa 
eras 
|| 
TT 
secenseas 
ane 
Bobs 
— 
at 
EH 
oa 
; 
ane 
MJ 
CSR. 
° 
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ed 
Mar Ael May SJunc July Aug Ser Oct Nov re 
Fig. 17. Curve for total Diatoms in 1907. 
was so abundant in 1907, was very poorly represented 
this year; while some of our 1908 collections have been 
unusually rich in Peridinians. Noctiluea (fig. 18), 
has been unusually abundant this autumn. Mr. Scott 
collected a pure sample of 150 ¢.c. on September 25th, at 
_ Piel, and estimated that there were then two millions per 
gallon in the water of the Barrow Channel. 
I now turn to some of the conclusions that were 
drawn in the last Sea-Fisheries Report from a study of 
the detailed figures for 1907; and I shall illustrate them 
by a few diagrams which were used in a Presidential 
address to the Linnean Society last May. The blocks 
have been kindly lent by the Council of that Society. 
E 
