SEA-FISHERIES LABORATORY. 981 
Diatoms which show clearly the distinctness of those that 
form the April and the June maxima. 
The distribution of these species throughout the 
years 1908 and 1909 agrees well with the above record 
for 1910; but 1907 seems somewhat different, as in that 
year Chaetoceras contortum and Thalassiosira norden- 
skioldi were very abundant species in April, and 
Rhizosolenia semispina reappeared in September in great 
quantity. 
THE VERTICAL HAULS IN THE Bay. 
As is stated above, we have this year a series of 
additional hauls in the bay, taken near the entrance 
with the fine net raised vertically through six fathoms 
from the bottom to the surface. The net was sufficiently 
weighted to keep the tail extended vertically, and care 
was taken that only the weight touched the bottom. 
The catches obtained, although naturally much 
smaller in bulk, give quite a satisfactory sample, and in 
their results throughout the year agree very closely with 
those of the surface nets. 
We give here a diagram (fig. 5) showing the curve 
of total plankton throughout the year as given by the 
ae ee 

Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 
Ab 
