1912] Esterly: Copepoda of the San Diego Region 309 
frequencies are not so high then as at other times. The low 
frequencies throughout table 33 give some idea of the rarity of 
Labidocera at the surface, and on the whole the results of sur- 
face hauling are rather obscure except in the matters just 
pointed out. 
Labidocera appears to be found only above 100 fathoms; it 
was not obtained in vertical closing hauls below 75 fathoms. 
There were 11 of these hauls and 21 animals were obtained, the 
majority (16) at night. In the absence of any successful hauls 
with the horizontal closing nets, it is difficult to say where the 
day plurimum is located; it is barely indicated by the vertical 
nets as between the surface and 5 fathoms. 
The lowest and highest surface temperatures and salinities 
for Labidocera were, respectively, 1321 and 2223, and 33.563 
and 33.704. 
Euchirella pulchra was obtained at the surface in seven hauls 
which captured 17 animals. One day haul took one animal; 
the other 16 animals were obtained in six night hauls. The 
lowest temperature at the surface when this species was taken 
was 13°8, the highest 19:9; the lowest and highest salinities 
were, respectively, 33.536 and 33.648. Figure 5 shows the 
time of greatest abundance at the surface; the numbers of 
animals given in the figure are reckoned on the basis of one- 
hour hauls and then increased ten times. 
NOP Onn Arann 
9 
8 
7 
6 
5 
4 
3 
: 
- 
il | a | 
4-6 6-8 8-10 10-12 12-2 
P.M. A.M. 
Fig. 5. Euchirella pulchra. Variations in numbers per ten hours of 
hauling at the surface during the night. 
