two streams, 
Vol. IX, Nos. 8-9.] Biological Work of the ‘‘ Investigator.’’ 363 
[N.S.] 
During the second season 1911-12 a further attempt was 
made to investigate the changes in the salinity : 
there was no available apparatus on board for 
every hour, both at station 399 at the mouth of Tavoy River, 
and in Port Owen, Tavoy Island, during a period of twelve 
e rise and fall of the tide. 
of AgNO. 
deci-normal strength, but as this could not be done very accu- 
rately the resulting figures have only a relative value. 
The results are given below—figs. 5 and 6—and they show 
‘very clearly that here at any rate there is a distinct fall in 
the salinity during the flood tide and a rise at the ebb. 
SL4) + 
é 
| eo 
ee 
ae 
ae 
a 
oS 
<a 
Loar 
-orro 
or niga!) 
$ 
° 
‘tom 8. 9 10, N12. lama. 3, * 5 6 7 6 
Mouth of Tavoy River 
Fia@. 5. 
* . . . ite to 
In this region the set of the tide is the exact oppos! 
what it isin the northern area. The ebb tide runs N.N W. 
S.S.E., and the results obtained at the different 
localities, combined with a study of the tidal currents, tend to 
ing down the Tavoy River, there is an area of lessened comes 
created in the region round the river-mouth. When the ide 
commences to flood, a strong current sets 1n from the — 
re, and runs in an easterly direction between the 
i N.W. 
direction between the South Moscos and the mainland, and 
the other to the §.8.E. between Tavoy Island and the coast. 
Asa resultthe water of the area of lessened salinity is swept 
