50 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
chusetts Bay in the first half of July, (Station 2 ') shows (fig. 8, 11) that 
there is a very rapid decline in temperature from the surface where it 
is about 65°, to 49° at about ten fathoms, followed by a rather slower 
decrease to 40.3° at about thirty-five fathoms, from which point down- 
ward to the bottom there is no further change. In the shallower parts 
of Massachusetts Bay in July, Stations 5 and 6 (fig. 9) the cooling 
between the surface and ten fathoms is even more rapid, the drop 
being from 61° to 43.4°; and it then declines less rapidly just as at 
Station 2, to the bottom in twenty-thirty fathoms, at which point the 
lowest temperature, 41.3° is reached, the temperature at this level 
F,, 40°41 42 43 44 45°46 47 48 49 50°51 52 53 54 55°56 57 58 59 60°6! 62635 64 65° 66 
Fa 
=" 
10 
15 
20 
25 
Ce ee st eikis met 
gist ieee ee! 
Pe ass oS is HB 
A i a a A A 2 
Fie. 11.— Temperature sections in the mouth of Massachusetts Bay (Station 
2), and west of Jeffrey’s Ledge (Stations 11, 14). 
being the same as it was at Station 2. In the Bay at the end of 
August conditions are different, as pointed out below. At Station 1 
the temperature curve is practically the same as at Stations 5 and 6, 
the temperature at the bottom in thirty-five fathoms being 40.6°, 
very nearly what it is at Station 2 at a corresponding depth. 
The section in the 100 fathom basin off Cape Ann, Station 7, 
(fig. 10) shows that the surface layer of warm water was slightly 
thicker here, the drop from the surface to 10 fathoms being only from 
64° to about 53°; and the rate of decrease diminishing slowly until 
the minimum of 40.3° is reached at fifty fathoms, instead of at thirty- 
*To agree with the station numbers of the U. S. Bureau of Fisheries 10000 
should be added to the numbers given in this report, e. g. 10002. 
