'M bulletin: museum of comparative zoology. 



far off shore (Plate 3) ; but it then approaches the coast once more, 

 water of this or higher salinity washing the outer islands from Mt. 

 Desert to the Grand Manan Channel. The salinity of the whole of 

 the Gulf to the south and east of this curve was probably above 32.4; 

 but we have no data on the salinity in the head of the Bay of Fundy. 



It is probable that the curve of 32.6 enclosed Cashe's Bank, where 

 the violent tides must cause an active vertical mixing of water, and 

 the Grampus crossed it about half-way between Stations 25 and 27, 

 whence it runs in a direct line northeastward, coming close to the 

 coast at Moose Peak. But the water in the Grand Manan Channel 

 was not so salt as this. Whether or not this curve entered the Bay 

 of Fundy is not known; nor can we absolutely establish the occur- 

 rence of water with salinities between 32.4 and 32.6 along the west 

 coast of Nova Scotia; but the facts that water only slightly more 

 saline was found at Station 29 on German Bank, and that there is 

 a considerable discharge of fresh water from the numerous small rivers 

 along this coast suggest that the coast water was fresher than 32.6. 

 Surface salinities above 32.6 were encountered generally over the 

 eastern arm of the deep basin, the value at Station 27 being 32.6; 

 Station 28, 32.75; Station 29, 32.7; and Station 31, 32.84. Unfortu- 

 nately no sample was collected at Station 30. 



Salinity at intermediate depths. — The table of salinities (p. 139) shows 

 that in no case was the water saltest on the surface; while at most of 

 the stations there was a rapid increase in salinity from the surface 

 downward, though the rate varied in different localities, as shown by 

 the sections (fig. 21-28). At five Stations, 2, 7, 11, 27, 43, samples 

 were taken at three or more levels, thus allowing a satisfactory plotting 

 of curves for the mouth of Massachusetts Bay, off Cape Cod, the 

 western and eastern arms of the 100-fathom basin, and the trench west 

 •of Jeffrey's Ledge. At the other stations only surface and bottom 

 salinities are known; consequently the curves are only approximate. 

 But inasmuch as the known curves are all practically parallel down to 

 fifty fathoms or so, they give a guide for reconstructing the others. 

 The type of curve is strikingly different from the temperature curves, 

 being regular and gradual, without the sudden dislocations which 

 characterize the latter, though the increase in salinity is usually 

 most rapid between the surface and fifty fathoms. They show, 

 furthermore, that over the deeper parts of the Gulf the increase in 

 salinity noted on the surface as we go eastward from Cape Ann, 

 extended to the intermediate depths and to the bottom as well. Thus, 

 taking successively Stations 7, 23, 27, 28, (figs. 21, 22) the curves show 



