branner: the stone reefs of brazil. 



43 



of the Cunhahu river, 

 where several fragments 

 are exposed at low tide. 



The total length of 

 the outer reef, including 

 the Sibauma end of it, 

 and making no allowance 

 for breaks and bars, is 

 8.4 kilometres. It is 

 possible, however, that 

 the whole of the north- 

 ern end was not seen, as 

 the tide was high when 

 this part of the coast 

 was reached. 



The pieces that form 

 the southern end of the 

 reef were not inspected, 

 hut observations were 

 confined to the portions 

 accessible from the 

 heach at low tide. These 

 portions, however, form 

 the great bulk of the 

 reef. South of the bar 

 the outer reef has so pro- 

 tected the embayment 

 that the water is very 

 shallow, and at low tide 

 one can walk out to and 

 beyond the fragments of 

 the inner reef then ex- 

 posed. The sand flats 

 between the laud and 

 the reef contain many 

 mollusks similar to those 

 whose skeletons are 

 found in the reef rocks. 



Just north of the Cun- 

 hahu har the reef is 

 twenty metres wide. 

 This portion of it grad- 

 ually approaches tlie 



P^ 



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