PLANKTON OF THE GULF OF MAINE 



331 



present time we have made only 9 horizontal tows at depths of 200 meters or more 

 within the gulf, in six of which Eukrohnia occurred. 



It follows from the hathymetric 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 hamata 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 03° 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 



