PLANKTON OF THE GULF OF MAINE 
305 
Percentages of the several species of copepods in samples from the horizontal hauls, December, 1920, and 
January and March, 1921, identified and tabulated by Dr. C. B. Wilson — Continued 
Station number 
10496 
10497 
10499 
10500 
10502 
10505 
10506 
10507 
10508 
10509 
10510 
10511 
Month.. 
January 
March 
Day of month.. 
1 
1 
4 
4 
5 
4 
4 
4 
4 
5 
5 
6 
Depth, in meters, of major part of haul. 
100 
50 
150 
60 
150 
20 
10 
60 
40 
150 
175 
100 
HORIZONTAL NET, OPEN 
Acartia clausi 
5 
2 
10 
5 
5 
3 
15 
5 
10 
5 
Acartia iongiremis 
2 
1 
T. 
2 
2 
Calanus finmarchicus 
65 
35 
75 
35 
10 
45 
45 
50 
50 
70 
30 
70 
Calanus hyperboreus 
2 
2 
5 
2 
Centropages bradyi ... 
T. 
C entropages hamatus _ _ _ . 
3 
16 
2 
5 
Centropages typicus .. 
5 
8 
3 
3 
1 
1 
Eucalanus attenuatus 
T. 
Euchaeta norvegica 
2 
2 
T. 
30 
Gaidius tenuisplnis 
in 
11 alithalestris croni .. 
5 
1 
1 
Labidocera aestiva. 
i 
Metis ignea 
T. 
Metridfa longa 
10 
8 
10 
30 
25 
5 
20 
10 
15 
15 
10 
Metridia lucens 
5 
8 
30 
5 
2 
T. 
5 
5 
Paracalanus parvus 
2 
10 
5 
1 
Pseudocalanus elongatus 
5 
14 
5 
10 
45 
45 
25 
25 
3 
10 
5 
Rhincalanus cornutus 
1 
Temora longicornis 
10 
1 
Tortanus discaudatus 
7 
Development stages 
C. 
C. 
C. 
A. 
c. 
A. 
c. 
F. 
Supplementary note on tlie copepods 60 
Since the preceding account of the copepods was written. Dr. C. B. Wilson has 
made a further examination of the tow nettings of 1920 and 1921 and communicates 
the following notes on additional species detected. Most of these appear only in 
very small numbers. One, however — Oithona similis — -is plentiful enough to suggest 
that it will prove widespread in the gulf. 
Aegisthus mucronatus. — A single female was obtained from a vertical haul at 
station 20069, March 12, 1920, southeast of Georges Bank. 
Alteutha depressa. — About a dozen of these peculiar harpactids, which look very 
much like sowbugs, were taken in a vertical net at station 20117 on April 17, 1920, 
close to the eastern shore of Cape Cod. 
Amallophora magna. — Three females taken in a vertical net just off the southern 
edge of Georges Bank, February 22, 1920, station 20044. 
Calanus minor. — Ten of these tiny calanids were taken at the surface between 
the eastern end of Georges Bank and Nova Scotia, April 16, 1920, station 20106. 
Calanus tonsus. — Six females were taken in a vertical net off the eastern end of 
Georges Bank, April 16, 1920, station 20107. 
Candacia norvegica. — Three females were captured at the surface off the southern 
edge of Georges Bank, May 17, 1920, station 20129. 
Chiridius armatus. — Eight specimens, including both sexes, were taken in a 
vertical net southeast of Nova Scotia, March 19, 1920, station 20077. 
19 Communicated by Dr. C. B. Wilson. 
