404 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
occasional diatom (Rhizosolenia), and a good many copepod eggs and 
nauplii. Schools of pollack (Pollachius virens) were spawning near 
by, and consequently it is rather surprising that our hauls contained 
very few of their eggs and only two pollack fry. And throughout the 
spawning period, which lasted until January, the eggs were only very 
sparsely represented in the plankton catches; but with the haddock 
in spring the case was quite the contrary. 
We found much the same type of plankton in early December, and 
though the catch, taken at its face value, would suggest a quantitative 
increase; the hauls are not comparable with one another though of the 
same length, because all were horizontal, while the speed of the vessel 
varied more or less. Furthermore, one might, another might not, 
pass through the zone of maximum richness; so that all they can be 
expected to yield in the way of quantitative results is whether the 
plankton was scanty, notably rich, or intermediate. The greater 
mass of the haul still consisted of Calanus finmarchicus, with a few 
Euchaeta norvegica. Sagittae were about one half as plenty in bulk 
as the copepods, chiefly S. elegans, with a few S. serratodentata; and as 
usual, Euthemisto was a conspicuous member of the plankton; the 
only coelenterates were a few Pleurobrachia mleus. The microplank- — 
ton had not changed appreciably since November, being still very 
scanty, chiefly Ceratium tripos, with an occasional C. fusus and Peri- 
dinium, and very few diatoms, chiefly Chaetoceras. | 
As the winter advanced, and the water grew colder and colder, there 
was little noticeable change in the general type of the plankton. Thus | 
on January 16th (St. 10,050) the bulk of the haul consisted of Calanus 
finmarchicus as usual, and of Sagittae, chiefly S. elegans. But though — 
no Euchaeta were taken, the net yielded four specimens of the large — 
northern copepod Calanus hyperboreus, a species not previously taken 
in the Bay, though we obtained it in other parts of the Gulf in summer 
(Loc. cit., p. 102). The haul also contained a few Sagitta serrato- 
dentata, appendicularians (Oikopleura) Tomopteris helgolandica, and 
Clione limacina, all of which occurred more or less frequently in sum- 
mer. Euthemisto, too, was plentiful. Two species of fish eggs were | 
numerous, but no fish fry. The microplankton was still very scanty; |) 
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but diatoms, chiefly Chaetoceras, with a few Coscinodiscus and Tha- 
lassiothrix nitzschioides now formed about one half its mass. 
At the end of January, the tow in Massachusetts Bay was quanti- i 
tatively about the same, with the addition of a few specimens of the — 
large copepod Euchaeta; but Sagittae formed fully half its bulk. In 
Ipswich Bay, however, on the same day (St. 10,052) there were only 
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