428 
BULLETIN OF THE BUREAU OF FISHERIES 
taken at this 
station ex- 
tended to a 
pth of 45 
eters. (See 
fig. 1.) In gen- 
eral, the aver- 
age number of 
organisms ob- 
at these 
stations 
was within the 
range of varia- 
tion of dupli- 
cate samples 
taken at a sin- 
gle station. A 
twofold or 
threefold vari- 
ation in num- 
ber may be ex- 
pected in cer- 
tain forms in 
duplicate catches, and most of the forms in the various series taken at these two 
stations fall within 
this range. 
At station 1 on 
July 19, 1927, the 
average number of 
Copepoda in the 
upper 50 meters 
was 13 per liter and 
5.5 per liter down 
to 45 meters at sta- 
tion 2 ; for the same 
strata the nauplii 
averaged 19 per 
liter at station 1 
and 15 per liter at 
station 2, while the 
Rotifera averaged 
350 at station 1 
and 360 at station 
2. There was an 
eightfold difference 
in favor of station 2 
in the green algae 
j £ / u j'f 1930. A, Diaptomus; B, Cyclops; C, nauplii; D, Cladocera; E, Rotifera; F, blue-green algae; 
and a fivefold dlf- G, green algae; H, diatoms 
Figure 5.— Vertical distribution of the net plankton in Karluk Lake, station 1, July 12, 1930. A, Diap- 
tomus; B, Cyclops; C, nauplii; D, Rotifera; E, blue-green algae; F, green algae; G, diatoms. The 
number of Cladocera was too small to be indicated in the diagram 
