246 
BULLETIN OF THE BUREAU OF FISHERIES 
Indian Ocean (van Breemen, 1908), it is known only from the North Atlantic and 
polar oceans. It is commonly distributed over the parts of the polar basin crossed 
by the Frarn on her famous drift (Sars, 1900); in the Kara Sea; between Norway, 
Spitzbergen, Greenland, and Iceland; and southward regularly to the Greenland- 
Faroe and Faroe-Shetland channels. It is widespread in the Norwegian sea, nu- 
merous in the deeps of the Norwegian fjords, and occurs southward to the Skager- 
Rak, where it is usually present in fair numbers. There are isolated records of it 
in the central part of the North Sea, and it has been taken to latitude 55° 23' N., 
longitude 11° 6' W., west of Ireland (Wolfenden, 1904), this being the most southerly 
record of it off Europe. 
On the American side it is recorded from Baffin Bay and from the Arctic coasts 
of Alaska and western Canada (Willey, 1920), hence is no doubt circumpolar. On 
the east coast of North America the Canadian fisheries expedition found it wide- 
spread in the Gulf of St. Lawrence, over the continental shelf along Nova Scotia, 
and outside the neighboring continental slope, but, curiously enough, not at all in 
the Green Bank-St. Pierre Bank region off Newfoundland. It also occurs with some 
regularity in the Gulf of Maine and over the shelf south of Marthas Vineyard, which 
so far as known is its most southerly outpost along the eastern seaboard of America. 
Distribution in the Gulf of Maine. — M. longa was not recognized at any of our 
stations in the gulf during the summer of 1912 or the following winter, nor can it 
have been other than very rare during that period, if actually present at all, for Dr. 
C. O. Esterly examined many- samples of the copepods. In July and August, 1913, 
however, he detected it in small numbers at four stations east and north of Cape Cod 
(20 per cent of the stations). In the summer of 1914, as in 1912, not one was de- 
tected in the gulf, or for that matter along the outer coast of Nova Scotia, although 
special watch was kept for it; and if not actually altogether absent from the gulf 
then, it must at least have been extremely rare, for it is so easily distinguishable in 
general body form from its relative M. lucens that it could not have been overlooked 
had it occurred in such numbers as we have subsequently found in the gulf. The 
year of local abundance for it was 1915, when it was detected in vertical hauls at 
about 65 per cent of the stations right through the season from May to October. 
It again dropped wholly out of sight in the gulf in the summer and early autumn of 
1916, when it was not found in the preliminary examination of any of the hauls 
(Bigelow, 1922, p. 147), although this was a very cold season, which is evidence that 
the low temperatures of that summer were reminiscent simply of extreme winter 
chilling and of tardy vernal warming resulting from local climatic conditions, and not 
due to any unusual flood of cold northern water. A few M. longa must, however, 
have existed in the gulf during the autumn of 1916, for Willey (1921) reports it as 
occasional at St. Andrews on November 2 and December 8 of that year, with a scatter- 
ing of it in the tow on February 23, 1917. 
Owing to the interruption of all oceanographic research in the open gulf by the war, 
no information is available as to the local status of M. longa during the remainder 
of 1917, 1918, or 1919, but it occurred in 81 percent of the vertical hauls during the 
spring (March to May) of 1920 and at 90 per cent of the stations during December 
of that year and in January and March of 1921 (tables, pp. 299, 304). Thus it 
