BRANNER: THE STONE REEFS OF BRAZIL. 87 
are no indications of a northward continuation of it 
in the sunken rocks further out, and over which the w 
tide. These breakers lie in the axis of the stone reef, 
There is a coral reef off shore at Praia, 
the stone reef ; possibly it is built upon 
The outer or northern end of the 
A coral reef beginning here on the e 
toward the south, and, being separa 
» unless they be 
aves break at low 
da Gamella also in the axis of 
a base of sand rock, 
stone reef is covered with barnacles. 
ast side of the rock roof bends back 
ted from it by a channel, protects it 
Fic. 54. Longitudinal section of an undermined 
portion of the stone reef, 
Rio Formoso. 
from the force of the waves of the open ocean. 
ward or northern ends that these two reefs 
arating them becomes wider and wider till it passes the Barreta das 
Jangadas, and at this end it is more than a hundred metres in width. 
This channel has a bottom of coarse calcareous sand with very fine mud 
in some places. Corals and other organic calcareous growths have 
spread over the outer side of the sandstone reef, and in many pl 
have grown upon the stone reef ав а base until they 
Surface of the water. 
It is noticeable that we here have corals thriving in front of a river 
mouth. The fact is that the stream is deflected to the north by the 
mmm --- = -- 
a PR | IN 
55. Across Rio Formoso stone and coral reefs. The darker portions are corals. 
It is only at their out- 
are joined; the channel вер- 
асев 
are now near the 
un dX 
Fic. 
Stone reef which thus protects the corals from the mud and fresh water 
entering from the river. A similar state of affairs 18 
other places along this coast. 
From the land end of the stone reef, following southward along the 
sandy beach to a distance of eighteen hundred metres, there is another 
(or the Same) stone reef joined to the land and running out into the 
embayment so as to make an angle of about twenty degrees with the 
beach. This reef is about seventy metres wide, Just where it joins 
the beach the rock is the coarsest seen in this vicinit 
found at several 
y, the pebbles 
being as big as pigeon’s eggs. The piece is only short, being about 
