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bulletin: museum of comparative zoology. 



the bottom, than off Montauk or south of Nantucket Shoals; and that 

 the transition between the two waters was very sudden. In the 

 profile from off Barnegat to the continental slope in about latitude 39° 

 (Fig. 40), water of 35%o washes the slope below about sixty fathoms, 

 and the curve of 35%o, which may be taken as an arbitrary division 

 between coast and Gulf Stream water, is almost vertical. Generally 

 speaking, too, the surface water was Salter along this whole profile 

 than in the preceding one, except at Station 10070; an exception ex- 

 plained by the fact that this part of the profile cut the southerly tongue 

 of surface water fresher than 32.4%o, noted above (p. 187, Plate 2). 

 Neither band B nor C can be traced as far south as this profile. But 

 Band A is still evident, with precisely tlie same salinity (33.2%o) as in 

 the two preceding profiles, washing the bottom rather nearer shore 

 than was the case further north, and gradually merging into the Gulf 

 Stream water of 35%o on its off shore side, instead of being limited sea- 

 ward by a sudden transition 



zone. On the other hand 

 there is a great difference in 

 salinity between it and the 

 surface water over it, and also 

 between it and the zone of 

 water closer to shore. 



The partial profile off Cape 

 May is instructive chiefly be- 

 cause it shows no sign of band 

 A ; hence it is safe to conclude 

 that the latter comes to an 

 end north of Delaware Bay. 

 The profile is otherwise so 

 much like the preceding one, 

 that I have not thought it 

 necessary to reproduce it 

 here. But the next one (Fig. 

 41), which is south of Dela- 

 ware Bay, reveals an entirely 

 new phenomenon, namely, a tongue of salt off shore water with salinity 

 of 35%o or more, intruding into the intermediate depths over the 

 continental shelf, with fresher water both above and below it. Its 

 landward end lies about over the thirty fathom curve, where the bot- 

 tom water has a salinity of about 34.3%o, with 33.24%o on the sur- 

 face. Apart from the salt tongue, the salinity as a whole is higher 



Fig. 41. — Salinity profile across the continen- 

 tal shelf south of Delaware Bay (Stations 

 10079, 10074). 



