SOURCES OF MARINE FOOD. 
361 
\ Letter M, September 27, 1894, 11.35 a. ru. at Station A, low-water slack ; reaching Station D 
I at 3.20 p. m., third hour of flood tide; wind southeast, force 5; sky partly cloudy. 
Organisms. 
Surface. 
Middle. 
Bottom. 
Stations. 
A 
B 
c 
D 
Copepods 
23 
13 
13 
7 
8 
10 
24 
Peridinium 
53 
22 
20 
10 
43 
30 
12 
Exuviaella 
57 
49 
51 
24 
64 
50 
19 
Chfetoceros 
1,424 
758 
407 
2, 241 
240 
104 
4 
Melosira 
339 
230 
202 
40 
439 
269 
23 
25 
29 
33 
18 
62 
7 
Rhizosolenia 
19 
23 
20 
7 
23 
30 
2 
Navicnla 
23 
29 
20 
12 
29 
26 
5 
Total 
1,940 
1,140 
753 
2, 334 
856 
571 
72 
Average temperature (°F.) . . 
66. 1 
66.5 
65.3 
62 
Depth (fathoms) 
■i 
0 
8.5 
15 
In this table the copepocls are estimated, upon a different basis and are therefore 
not added in making up the totals. Otherwise all the organisms of the surface of all 
the stations are added into the first column of numbers, all those from the mid-depth 
into the second column, and all those from the bottom into the third. So also the 
same numbers are properly distributed according to their occurrence at the respective 
stations A, B, C, D, the total sum of the surface, mid-depth and bottom being repre- 
sented in each number. Such a table shows in the first place that the sum total of 
all these organisms at the surface is greater than those of mid-depth, which latter are 
in turn more abundant than those of the bottom. Also that this is the rule for each 
separate factor of the series except the Exuvicella , least at mid- depth, and the Lauderia 
forms, which are slightly most abundant at bottom, and the Rhizosolenia and Nnviculn 
forms, which are most abundant at mid-depth. Similarly the sum total of all the various 
groups of organisms at A is much greater than at any of the succeeding stations, the 
numbers diminishing very rapidly, especially between A and B, and between 0 and 1). 
It is to be noted, however, that this remarkable abundance of material at A is due very 
largely to the item Chcetoceros , with its abundant Melosira costata, and if this be left 
out of the calculation, Station A will be seen to be next to D as regards numbers, 
being much less than either 0 or B. Station B is the richest in these organisms, all 
reaching their maximum excepting Lauderia and Rhizosolenia , which increase to Station 
(3, especially at bottom. The copepods also increase most rapidly from C out to D. All 
of these features are analyzed into their component parts by the platting on plate 6S, 
from which the distribution of these several forms may be compared. 
The same section run three days earlier is represented in the same way by the 
platting on plate 69, and the totals of the organisms by the following table: 
( Letter K, September 24, 7.45 a. m. at Station A, low-water slack; 11.53 a. m. at Station D, 1 
) third hour of flood; wind north- northwest, force 5 ; sky clear. \ 
Organisms. 
Surface. 
Middle. 
Bottom . 
Stations. 
A 
B 
c 
D 
Oopepods 
13 
5 
6 
4 
2 
6 
12 
Peridinium 
59 
13 
7 
14 
23 
"THT 
“ 4 
Exuvisella 
65 
39 
25 
38 
36 
52 
3 
Chfetoceros 
1,891 
1. 273 
1,126 
3,609 
CIO 
67 
4 
Melosira 
266 
91 
60 
87 
170 
146 
14 
21 
8 
13 
2 
25 
31 
15 
Rhizosolenia 
24 
11 
14 
5 
12 
i 
Navic.ula 
19 
18 
30 
14 
18 
31 
4 
Total 
2, 345 
1,453 
1,275 
3,767 
871 
390 
45 
Average temperature (°E.) . . 
Depth (fathoms) 

70.5 
4 
69 
7.5 
67.5 
7.5 
64 
15.5 
