Mr. John Murray stated that " if we except Bermuda and 

 one or two other outlying reefs where the temperature may 

 occasionally fall to 66'^ Fahr. or 64° Fahr., it may be said that 

 reefs are never found where the surface temperature of the 

 water, at any time of the year, sinks below 70° Fahr., and 

 where the annual range is greater than 12° Fahr. In typical 

 coral reef regions, however, the temperature is higher and 

 the range much less." No regular series of records of the 

 temperature of the water in the coral-bearing Gulf of Manaar 

 has as yet been made. The surface temperature, which I 

 recorded from time to time during my visit to Edmesvaram 

 island in the latter half of July 1888, varied from 79° Fahr. to 

 91° Fahr. between the hours of 7 a.m. and 6 p.m. 



The following table shows the temperature range of 

 Tuticorin during the year 1887, the readings being taken in 

 the shade at 10 a.m. and 4 p.m. : — 



Tuticorin has been celebrated for its pearl fishery from 

 a remote date, and, as regards comparatively modern times, 

 Friar Jordanus, a missionary bishop, who visited India about 

 the year 1 330, tells us that as many as 8,000 boats were then 

 engaged in the pearl fisheries of Tinnevelly and. Ceylon.^ 



In more recent times the fishery has been conducted, 

 successively, by the Portuguese, the Dutch, and the English. 

 The following excellent description by Martin of the pearl 

 fishery in the year 1700, during the Dutch occupation of 

 Tuticorin, shows that the method of fishing adopted at that 

 time agrees, in its essential characters, with that which is in 

 vogue at the present day : — 



" In the early part of the year the Dutch sent out ten or 

 twelve vessels in different directions to test the localities in which 



' Streeter, Pearls and Fearling Life, 1886. 



