36 
BULLETIN OF THE BUREAU OF FISHERIES 
The pelagic eggs of the many species of fish that spawn on the banks or in shallow 
water alongshore in the gulf are as rarely found in our tow nettings outside the 100 or 150 
meter contours as are other neritic organisms. Cod, haddock, and several species of 
flatfish may serve as examples of this; likewise the silver hake (Bigelow and Welsh, 
1925, p. 488, fig. 217, and p. 244); while the eggs of the cunner are closely confined 
to the coast line and to the vicinity of the outer islands and shoals (Bigelow and 
Welsh, 1925, p. 284). 
The locality records for the neritic animals just summarized, and for sundry 
others belonging to the same category, are concentrated in a rather narrow coastal 
zone paralleling the periphery of the gulf and over its shallow southern rim, with 
neritic forms very seldom of any importance in the planktonic community more than 
a few miles out at sea in summer, except for the shallow offshore banks. The fact 
that most of the animals of this category, if not wanting in the central basin of the 
gulf, are at least so scarce there as to have been overlooked, is sufficient evidence 
that the plankton of the coastwise belt has little tendency to disperse seaward at 
that season, but that the eddylike circulation parallels the coast, which is corroborated 
by drift bottles and by oceanographic evidence generally. 
With few exceptions the scarcity of pelagic animals of neritic origin in the offshore 
parts of the gulf leaves the planktonic communities that people its open waters (not 
only in the central basin but right up to the outer headlands) composed of animals 
and plants not only independent of the bottom at all times but most of which are 
equally oceanic as opposed to neritic in European waters, as appears from the very 
extensive records accumulated by the International Committee for the Exploration 
of the Sea. However, they are not the product of the Atlantic basin outside the 
continental slope* as the term “oceanic” might imply, but of the banks water that 
washes the continental shelf on both sides of the Atlantic, and to which they are 
confined off the North American littoral by the high temperatures of the tropical 
water farther offshore. 
The diatom plankton encountered over the basin in May, 1915, typified by Chseto- 
ceras densurn and Rhizosolenia semispina, belongs to this category (p. 434; Gran, 1915; 
Ostenfeld, 1913; Herdman and Riddell, 1911), while the Ceratium community, 
which usually occupies the Gulf of Maine as a whole throughout the summer (p. 391), is 
also characterized by species ( Ceratium tripos and C. longipes var. atlantica ) usually 
regarded as oceanic in the North Sea region (Paulsen, 1908; Jorgensen, 1911) 
and in the Norwegian Sea (Gran, 1902). This is equally true of most of the pelagic 
animals most constantly characteristic of the plankton of the gulf; for example, of the 
copepods Calanus jinmarchicus, Pseudocalanus, Euchaeta, and Metridia (Dam as, 
1905; Gran, 1902; Farran, 1910; Herdman and Riddell, 1911); of the amphipods 
Euthemisto bispinosa and E, compressa (Tesc-h, 1911; Sars, 1895); of the pteropod 
Limacina retroversa (Paulsen, 1910); and of the euphausiid shrimp Thysanoessa 
inermis (Tattersall, 1911; Kramp, 1913a), to mention only a few of the most typical. 
While two of themos timportant of its members, faunistically ( Sagitta elegans and Mega- 
nyctiphanes norvegica), are intermediate between oceanic and neritic in their biologic 
status in the North Sea region (Apstein, 1911; Kramp, 1913a), in the Gulf of Maine 
they cover practically the same range as the more typically oceanic forms just men- 
tioned. Off the European coast most of these species — in fact, the Calanus commu- 
