404 BULLETIN: MUSEUM OF COMPARATIVl 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 

 spa'^ATiing 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 the}^ 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 Plcurobrachia pileus. The microplank- 

 ton had not changed appreciably since November, being still very 

 scanty, chiefly Ceratium tripos, mth 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 hyperhoreus, 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) Tomoptcris 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; 

 but diatoms, chiefly Chaetoceras, with a few Coscinodiscus and Tha- 

 lassiothrix nitzscliioides now formed about one half its mass. 



At the end of January, the tow in Massachusetts Bay was quanti- 

 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 



