40 
BULLETIN OF THE BUREAU OF FISHEKIES 
Euchseta, Sagitta elegans, Eukrohnia, Euthemisto of both species, Clione, Limacina 
retroversa, Tomopteris, Meganyctiphanes, Thysanoessa inermis, and Th. longicaudata. 
This is a list that might be expected in summer or autumn, and the same was true of 
the hauls made in Massachusetts Bay during the winter of 1912-1913, mentioned 
above (p. 39). The plankton is as uniform, qualitatively, from season to season in 
the deeper parts of the gulf as the following table shows for a location in the western 
basin about 30 miles off Cape Ann. 
Zooplankton in the western basin, various months 
[D, dominant; X, occurred] 
Febru- 
ary, 
station 
20049 
March 
April, 
station 
20115 
May, 
station 
10267 
June, 
station 
10299 
July, 
station 
10007 
August 
Decem- 
ber, 
station 
10490 
Station 
20087 
Station 
10510 
Station 
10088 
Station 
10254 
Station 
10307 
Calanus finmarchicus 
D 
D 
D 
D 
X> 
D 
D 
D 
D 
D 
D 
Calanus hyperboreus 
X 
X 
x 
X 
Pseudocalanus elongatus 
x 
X 
X 
X 
X 
X 
Metridia lucens 
X 
x 
X 
X 
X 
X 
Metridia longa 
X 
Euchseta norvegica 
X 
D 
X 
D 
X 
X 
X 
D 
D 
X 
X 
Anomalocera pattersoni... 
x 
X 
X 
X 
Centropages typicus 
X 
Pasiphrea 
x 
x 
x 
X 
X 
Meganyctiphanes norvegica 
x 
x 
x 
X 
x 
X 
X 
X 
Thysanoessa inermis. 
x 
x 
x 
x 
X 
X 
X 
Thysanoessa longicaudata 
X 
X 
(?) 
X 
Thysanoessa gregaria 
X 
Euthemisto compressa 
X 
x 
x 
X 
X 
X 
Euthemisto bispinosa 
X 
Limacina retroversa 
x 
x 
X 
X 
Clione limacina 
x 
x 
x 
x 
x 
Sagitta elegans . 
X 
X 
X 
X 
X 
X 
D 
X 
X 
X 
X 
Sagitta serratodentata 
X 
X 
Sagitta lyra 
x 
x 
x 
X 
Eukrohnia hamata. _ 
x 
x 
x 
X 
X 
Tomopteris catharina 
x 
x 
X 
x 
X 
Aglantha digitale 
X 
x 
x 
x 
x 
BeroS cucumis 
X 
x 
x 
X 
Stephanomia... 
X 
x 
X 
X 
X 
Phialidium languidum 
X 
X 
Broadly speaking, our March hauls have paralleled those made in midsummer 
in the relative importance of the several groups of animals in different parts of the 
gulf, as well as in the qualitative composition of the catches. Thus, Pleurobrachia 
was dominant on German Bank both on March 23 and on April 16, 1920 (stations 
20085 and 20103), just as it usually is in summer and autumn, and its area of abun- 
dance extended from abreast of Yarmouth, on the north, to the shoals off Cape Sable, 
to the south, on both these visits. On both these spring visits there was a second 
center of abundance for Pleurobrachia on Browns Bank, where our June and July 
tows have yielded only an occasional specimen; but although the area of abundance 
for Pleurobrachia in this general region was more extensive in March and April, 
1920, than we have found it in summer, these ctenophores were less plentiful in 
actual number; nor had they so thoroughly exterminated the other smaller animals, 
for we found the German Bank-Cape Sable swarm accompanied by copepods in 
fair numbers on the April visit, besides barnacle (Balanus) nauplii (in abundance), 
Sagitta elegans, euphausiids, Euthemisto, and Tomopteris. 
