COPEPODS GATHERED BY ALBATROSS—WILSON 147 
ever, did afford a greater opportunity for the inclusion of the species 
frequenting the horizontal part of the tow. 
Regrettably, vertical tows with open nets give no idea of the depth 
at which various specimens entered the net. An electric light was 
used to lure the plankton on enough occasions to warrant the conclu- 
sion that it adds to the number of copepods captured. 
[ Descriptions of the several nets and pertinent physical station data 
will be found in the dredging and hydrographic records published for 
each Albatross cruise by the U.S. Fish Commission, later U. S. Bureau 
of Fisheries. These publications are cited on pages 352, 358, 360, 364, 
493 in footnotes accompanying the “Lists of copepods collected, 
arranged by stations.” —W. L. S.] 
GENERAL CONCLUSIONS 
Although the time of day, the temperature of the water, and the 
duration of the haul were recorded for each towing in the original 
Albatross dredging and hydrographic records, there was never any 
agreement between successive hauls except in temperature. Exten- 
sive comparison of the different hauls is therefore impossible and thus 
the number of species obtained would have little significance. Gen- 
erally, the number has not been discussed in the text or entered in the 
lists of copepods collected. A study of the lists of species collected, 
however, together with a review of the station records, emphasizes 
some facts worthy of consideration and permits some comparisons of 
interest with plankton lists of other expeditions. 
The first impression is one of great irregularity of distribution. 
The samples of plankton from 29 stations examined by the author 
contained no copepods. At each of some 100 other stations there was 
but a single species and sometimes only a singlespecimen. Otherwise, 
anywhere from 2 to 100 or more species were obtained at each station. 
Conversely, approximately 90 species were each confined to a single 
station, while the number of stations from which other species were 
recorded ranged from 2 to 50 or more. There were even greater 
differences in the number of specimens obtained at the stations. Some 
hauls yielded but two or three individuals, while in others the number 
often ran into hundreds and even thousands of specimens. 
The time of day most favorable to a large catch is late in the after- 
noon or early in the evening. 
While a horizontal surface tow nearly always yields a larger num- 
ber of specimens and a greater variety of species, there are stil! left 
quite a large number of species that appear only in vertical tows from 
various depths. By increasing the duration of a tow, an addition to 
its volume will be practically certain to result, but the increment is 
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