250 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. : 
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deep water off Platt’s Bank, where the stations were occupied within — 
six days of the same date. ‘s 
In the eastern basin, the water was considerably less salt in 1913 | 
than in 1912, although the two sets of observations were taken within — 
a few days of the same dates. On its western side (Station 10027, 
1912; Station 10092, 1913) the difference was greatest in the mid- 
depths (.35%p at fifty fathoms), very slight at surface and bottom; 
but further east (Station 10028, 1912; 10093, 1913), it was uniform 
(.3%o-4%o) all the way from twenty fathoms down to the bottom. 
And the 120 fathom salinity at Station 10028 in 1912 (34.54% ) is 
almost .3% higher than any salinity in 1913. In the northern end — 
of the basin, on the coastal bank near Lurcher Shoal, and off the 
northeastern coast of Maine the water was also slightly salter at all 
depths in 1912 (Station 10036) than in 1913 (Station 10097), though 
the two sets of observations were taken at nearly the same season, and 
the geographic locations were almost identical. But on German Bank 
the reverse is true, the water being about .05%9-.1%p saiter at all 
depths in 1913 than in 1912. The salinity of the coast water between 
Cape Ann and Cape Elizabeth was about the same in August, 1913, as - 
it was two to three weeks later in 1912, correspondingly salter than the 
July salinities of that year (1914a). Off Monhegan, where the observa- 
tions for the two years were taken at practically the same date, the 
water was slightly fresher on the surface, slightly salter at sixty fath- 
oms, in 1913 (Station 10102) than in 1912 (Station 10021). 
Thus, in brief, the Gulf was colder and fresher in its eastern, warmer, 
but of about the same salinity, in its western half, in 1913 than in 1912. 
In the preceding lines the differences between the ‘two years have 
been emphasized. But the most important general conclusion is that 
these differences are really very slight; and that the general distribu- 
tion of salinity, highest in the east, lowest in the west, was the same 
in 1913 as in 1912 
ORIGIN OF THE COAST WATER. 
In few parts of the world is the coast water so sharply defined by 
salinity, temperature, and color, from oceanic water, as it is over 
coastal shelf between Nova Scotia and Cape Hatteras. And not only 
are the physical differences great, but the transition from one type to 
the other is often surprisingly sudden. 
The general characteristics of the coast water, as they impress the 
