BRANNER: THE STONE REEFS OF BRAZIL. 55 
mouth of the river here a hundred metres wide. West of this branch of 
the river is exposed at low tide a portion of the inner reef, This inner 
reef is here from ten to eighteen metres wide and three hundred metres 
long; at low tide it connects with and forms part of the beach. The rock 
is in places of a reddish color, and is not as hard as that of the outer reef. 
Fifty metres west of the inner reef and exposed on the river bank at low 
tide is a soft pebbly sandstone, in texture very like the reef rock, but 
containing no shells and varying in color from a dark brown to perfectly 
black. These black beds underlie Mamanguape Point and are barely 
covered at high tide. The Mamanguape Point itself is of white sand to 
a depth of eight or nine metres, heaped up here by the wind, but thin- 
ning and disappearing east of the village of Barra do Mamanguape. Be- 
neath this sand the black rocks pass westward round the point and up 
the river to and beneath the village, above which it is still visible here 
and there. These black sandstones are about on a le 
reef, They appear to have been colored by organic matter, In places 
they are strongly false bedded. (Compare geology of Rio F Ormoso.) 
The consolidated beaches of Parahyba do Norte. 
the Rio Parahyba do Norte, State of Parahyb 
on which the lighthouse stands is of coral, 
second part of the present paper. 
Properly speaking, there is no sandstone reef in the vicinity of this 
port. The coral reef is only about one kilometre from the shore, with 
which it is parallel. From the Ponta da Matta southward for 
more than а mile the beach 18 low, flat, and s 
palms. Beyond this to the south begin to appear evidences of an old 
consolidated sand beach, and these signs continue for nearly twelve hun- 
dred metres. The beach, however, continues to be sandy, and the pen- 
insula west of it is still low and flat. Loose blocks of the sandstone of 
the consolidated beach are sparsely scattered over the beach in some 
places, and in others the bed is exposed in place. The exposures are all 
between high and low water marks, and so far ав was seen, ave confined 
to the beach, where they are generally overlain by a metre or more of 
sand and soil. 
vel with the outer 
— At the entrance to 
a do Norte, the great reef 
This will be described in the 
something 
andy, and planted with coco 
The peninsula lying between Rio Parahyba and the ocean is narrow- 
‚ and at or very near this 
each are uncovered. This 
e beginning of the 
‚and is nearer the swamp. 
the rock not very hard, and 
est one kilometre south of Fortaleza da Barra 
narrowest part the remains of a consolidated b 
exposure is between the village of Cabedello and th 
mangrove swamp on the right side of the river 
The exposure is between high and low tides, 
