208 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
depth, at the eastern than at the western side of the Gulf, down to 
about 100 fathoms, equal salinities being found about 15-20 fathoms 
deeper on the Massachusetts Bay than on the Nova Scotia side. _ 
Below 100 fathoms there was much less variation in salinity from west _ 
to east, depth for depth, the curve of 34% following the 110 fathom 
level right across the western basin. At 130 fathoms the salinity was 
almost precisely the same (84.1% g) in the two basins. 
The water was much fresher at the mouth of Massachusetts Bay 
ce 104 39 90 
(nr 
20 
we ~ ~s 
Me Ze LO 
Fic. 49.— Salinity profile from the trough between Jeffrey’s Ledge and the 
mainland (Station 10104) to the centre of the Gulf of Maine (Station 
10090). 
33.8% 
than further east, especially at the bottom, while the very sudden dip 
of the curve of 32.7% suggests that vertical circulation was active Mm 
the Bay. And this may well have been the case, as the tidal currents 
are of some strength in the neighborhood of Station 10106. The 
eastern end of the profile shows a sudden spreading of the curves over 
the coast bank, such as we found in 1912 (1914a), the range of salinity 
for the entire column of water on German Bank being only from 
32.79%o-32.94%o. The only exception to the rule that salinity m- 
creased from west to east is afforded by Station 10093, where the 
