254 bulletin: museum of comparative zoology. 



Ostenfeld, 1913; Herdraan and Ridell, 1911). And the Ceratium 

 plankton, which occupies the Gulf as a whole throughout the summer 

 is composed of species {Ceratium tripos, and C. longipes var. atlantica) 

 which are usually regarded as oceanic in the North Sea region (Paul- 

 sen, 1908; Jorgensen, 1911), and in the Norwegian Sea (Gran, 1902). 

 The same is true of most of the Metoza characteristic of the Gulf, for 

 example, the copepods Calanus finmarcMcns (Damas, 1905; Gran, 

 1902; Farran, 1911; Herdman and Ridell, 1911), Pseudocalanus, 

 Euchaeta and Metridia, (Farran, 1910; Herdman and Ridell, 1911): 

 the amphipods Euthcmisto bispinosa and E. compressa (Tesch., 1911; 

 Sars, 1890-1895); the pteropod Limacina balea (Paulsen, 1910 " Li- 

 macina retroversa''); and the euphausiid Thysanoessa incrmis (Kramp, 

 1913; Tattersall, 1911). Two other faunistically important members 

 of the plankton, Sagitta el^gans and Meganyctiphanes norvegica are 

 intermediate between oceanic and neritic in the North Sea region 

 (Apstein, 1911; Kramp, 1913). In the Gulf, however, they cover 

 practically the same range as the more typically oceanic forms just 

 mentioned. Furthermore, not only do these oceanic animals occur 

 generally over the central part of the Gulf, but they constitute the 

 bulk of the plankton even close to the land, except for a brief period 

 in early spring, when their place is taken by the vernal diatom wave 

 (1914b). 



On the other side of the Atlantic most of these species, most charac- 

 teristic of the Gulf plankton are oceanic, not only as opposed to 

 neritic, but as inhabitants of the neighboring parts of the Atlantic 

 Basin. This is also the case right across the North Atlantic, from 

 the Norwegian Sea and Iceland on the east, to Newfoundland and 

 Nova Scotia on the west (Herdman and Scott, 1908;- Murray and 

 Hjort, 1912). But thence southward, the band of cool water along 

 our coast is a sort of cul-de-sac for them, the Gulf Stream limiting 

 them on the one side, as the coast line does on the other; and most of 

 them probably are not endemic south of New York, though they may 

 appear there as immigrants from the northeast, in the southwest 

 current which prevails along that part of the coast (1915). 



Fish Eggs and young Fish. — The study of the fish eggs is much 

 faciliated by the fact that comparatively few species producing 

 pelagic eggs are common in the Gulf of Maine. Furthermore, the 

 eggs of most of the economically important fishes, e. g., Cod, Haddock, 

 Silver Hake, Hake, Mackerel, and several of the flounders, are easily 

 recognized; and as it happens, these species have usually composed 

 the bulk of the fish eggs collected. 



