PLANKTON OF THE GULF OF MAINE 331 
present time we have made only 9 horizontal tows at depths of 20U meters or more 
within the gulf, in six of which Eukrohnia occurred. 
It follows from the bathymetric status of Eukrohnia, as just outlined that this 
worm is practically confined to the offshore parts of the gulf (fig. 92), occurring only 
very rarely between the 100-meter contour and the coast; and while it may be ex- 
pected anywhere in tows of appropriate depth, the actual localities of capture have 
been concentrated along the eastern, northern, and western margins of the deep 
Fig. 93. — General distribution of the glass worm Eukrohnia hamala ofl the coasts of the northeastern United States and of 
eastern Canada. A half hour’s tow with a net 1 meter in diameter, at the appropriate depth, may be expected to yield 
up to 20 specimens in the lightly hatched areas, and more than 20 in the heavily hatched area. The chart east of 
longitude 63° is based on the published records of the Canadian fisheries expedition (Huntsman, 1919) 
basin, a reflection of its immigrant origin and of the anticlockwise eddy current with 
which it drifts once it is within the gulf. It has usually proved far more numerous 
along the eastern side of the basin from the Eastern Channel right up to the entrance 
of the Bay of Fundy on the one side of the gulf, and in the northern half of the 
western trough on the other, than in the intervening deep waters. In these two rich 
areas half an hour’s tow with a meter net at any level deeper than 100 meters will 
usually yield at least 20 Eukrohnia if it occurs at all (fig. 93); elsewhere it is usually 
