1912] Esterly: Copepoda of the San Diego Region 285 
The fact of diurnal migrating was clearly shown by hauls 
with the Kofoid net made in 1909. The discussion of those 
hauls, as already stated, is in a separate paper (Esterly, 1911b) 
and will not be repeated here. Table 14, which follows, is 
derived from the data obtained from hauls with the vertical 
closing nets. The hauls with these nets are not well distributed 
through the twenty-four hours: there are no hauls between 
8-10 10-12 12-2 2-4 4-6 6-8 8-10 10-12 12-2 2-4 4-6 
P.M. A.M. 
Fig. 1. Calanus finmarchicus. Variations in numbers per hour at surface 
according to time of day. Data in table 12. 
8 p.m. and 2 a.m., and none between 6 and 8 p.m. above 50 
fathoms; the day hauling was done between 6 and 12 a.m. and 
4-6 p.m., there being no collections from 12 o’clock noon to 
4 p.m. The frequencies in table 14 as in all others dealing 
with the vertical closing nets are “‘haul frequencies.’’? ‘‘Hour 
” 
frequeney’’ would be practically meaningless, since the nets are 
drawn at the same rate in all hauls. The averages expressing 
per fathom’’ for the same reasons. 
oe 
abundance are 
6-8 | 
a 
a 
