794 
BULLETIN OF THE BUREAU OF FISHERIES 
with our own data for 1914 (fig. 145) to show the isohalines for 35.5 and 36 per mille 
departing farther and farther from the continental edge, passing eastward from 
Georges Bank, and so leaving a less saline wedge (34.5 to 35.5 per mille) some 60 
miles wide off the mouth of the Eastern Channel. This fact is worth emphasis as 
one of the numerous bits of evidence that the indraft that takes place into the east- 
ern side of the gulf, via this channel, is constantly of the so-called “slope” origin 
2 $ <2 _ . 'o k s 
i\J .tv. Stations c\, «M oj 
Fig. 156 — Salinity profll ( running from a station (10213) off northern Cape Cod, southward across the western end of 
Georges Bank (stations 10215 and 10217), to the continental slope (station 10218), July 19 to 21, 1914 
(p. 842), thus accounting for the rarity of tropical planktonic animals and plants 
within the gulf (Bigelow, 1925). 
When the transition in salinity is as abrupt along the edge of Georges Bank as 
itjwas in July, 1914 (fig. 156), to speak of a salinity “wall” is excusable exaggera- 
tion. At such times the following waters may be named, successively, along any 
profile crossing Georges Bank from north to south: 
