82 University of California Publications in Zoology [ Vou. 14 
The other two stations, which did not lie along this main line, gave 
the following figures : 
H-5220 (D-5787).........---.----- 34.08 
H-5219 (D-5785).................. 34.04 
It will be seen that, with the exception of the first two stations 
listed, which show an evident reduction of salinity,?? the water at these 
outlying points exhibits practically the same degree of concentration. 
Indeed, the figure for station H—5225, ten miles distant from the 
Golden Gate, is exactly the same (34.05) as that for station H—5221, 
twenty-six miles distant. During October, at least, the influence of 
the water of San Francisco Bay would thus seem to be limited to a 
comparatively narrow zone immediately outside of the Golden Gate. 
Whether or not this is true during the spring season, when from ten 
to twenty times as much fresh water is passing out of the bay, we 
have at present no means of knowing. 
Excluding the two stations nearest to the Golden Gate, the mean 
salinity of these off-shore stations was 34.04. 
According to the salinity chart of Schott (1902), it would appear 
that the waters adjacent to the California coast, in the latitude of 
San Francisco, should have a concentration of less than 33.5 per 
mille, though the isohaline of 34 is represented as bending far to the 
northward as the coast is approached. It is not evident, however, to 
what degree Schott’s figures represent annual averages, and it is like- 
wise not stated how close to shore the observations were carried. 
According to the theory of upwelling, we should expect to find water 
of a higher salinity, derived from the deeper parts of the ocean, in 
the immediate neighborhood of the western coast. 
Some basis for a comparison between the salinity conditions of two 
successive years is afforded by the results of the supplementary obser- 
vations of July 18 to 23, 1913, already referred to in the chapter on 
temperature. 
The six hydrographic stations of the regular series which were 
revisited in July, 1913, gave a mean salinity which differed by only 
0.32 per mille from the mean of these stations for the same month of 
the preceding year. The 1913 readings were slightly lower on the 
average than the 1912 ones, the differences ranging from -+ 0.87 to 
— 1.73 per mille. Station H—5329, near the Golden Gate, may likewise 
be fairly compared with 4967 of the regular series, which was in the 
same vicinity. For the former station, twenty-eight samples taken 
22 The field records indicate an ebb tide at this time. 
