98 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
On the brow of this bluff stands the old town or upper city of Porto 
Seguro. The view from the edge of the plateau is remarkably fine, and 
throws much light upon the geographic history of the region. The ac- 
companying sketch was made from the southwestern edge of the plateau 
in the outskirts of the old town. 
It was made во late in the day, 
however, that the details of the 
hills on the south side of the val- 
ley could not be seen. South of 
the valley these same steep-faced 
hills continue down the coast. 
The valley of the Rio Cachoeira 
is flat-bottomed, here sandy and 
there covered by mangues that. 
extend back and up the smaller 
From a sketch made at 
channels from the margin of the 
main stream like fingers from a 
hand. This flat valley, about its 
lower end at least, is less than 
one metre above the highest tides. 
On the south side of the river is 
a caatinga forest where the land 
is four metres above mean tide 
(Wagoner). 
The Porto Seguro reef has its 
southern end joined to the land 
and lies square across the mouth 
the edge of the plateau at Porto Seguro. 
of the valley and of the Cachocira 
River, which it deflects northward. 
The main unbroken reef is one 
thousand six hundred metres long, 
but beyond this to the north and 
lying in the line of the reef are 
four separate pieces which add 
six hundred metres more to its 
length. It varies in width from one hundred and thirty-five metres near 
its southern extremity to thirty metres in the narrowest part of the main 
reef; throughout the greater part of its length it averages thirty-five 
metres. At high tide the water breaks over it the entire length, but it 
‘is more effective as a breakwater than the Pernambuco reef. Its general 
Ета. 64. The region about the mouth of Rio Buranhaem or Cachoeira. 
