SALINITY (PjRT5 PER THOUSAND) pH SALINITY (PARIS PER THOUSAND) pH OF WATER SALINITY (PARTS PER THOUSAND) 
68 
BULLETIN OF THE BUREAU OF FISHERIES 
2 4 6 0 10 12 14 16 19 20 22 24 26 20 90 I 9 3 7 9 II 13 IS 17 19 21 23 23 27 29 
MARCH APRIL 
Figure 10. — Charts showing the daily salinity and pH of water (surface) in Offatts Bayou from 
March to August, inclusive, and the daily set from May to August in the same place. The 
period of heavy setting at the middle of May took place on both reefs, while the light setting 
at the end of May and early in July occurred on the middle ground reef only. Shells placed 
on reefs August 19 were examined on the 27th and found to have a fair set of small spat, though 
counts were not made (points marked +) 
