358 Prof. Flartt on the Brazilian Sandstone Reefs. [June, 
in texture, and contains numerous fragments of corals and shells, 
the latter being frequently found entire. Many of the species of 
both exist in abundance throughout the bay. The upper part of 
the cliff is of almost pure sand, and has been so incompletely hard- 
ened as to crumble readily between the fingers. The amount of 
calcareous material in the lower portion is very great, and it is 
said to yield a good quality of lime on burning. 
Whether this cliff belongs to the same class of structures as 
the reefs or not, it is, at least, composed of the same materials, 
and must have been formed in about the same way. Its present 
elevated position—for high water reaches only slightly above its 
base—indicates that the shore has been raised at this point toa 
height nearly equaling that of the cliff What gives an increased 
interest to this locality is the presence of a low kitchen-midden, 
only two or three. feet thick, which overlies the entire cliff. It is 
composed of a dark-colored, sandy earth, packed full of the 
shells of the edible mollusks of the bay, with a few scattered 
bones, and occasionally a human skeleton. 
The stone reefs of the southern part of the province of Bahia, 
have been very fully described by Prof. Hartt, in the “ Geology 
and Physical Geography of Brazil.” The principal ones are those 
of Porto Seguro and Santa Cruz, both being similarly situated 
and of about the same character. The former is the larger, and, 
beginning in front of a small bay formed at the mouth of a river, 
runs southward, skirting the shore for a long distance. In gen- 
eral structure it is like the Pernambuco reef; the outer edge has 
become very jagged, from the undermining and falling down of 
blocks. But below the level of low water, the reef-rock extends 
seaward a hundred feet or more, forming a very shallow tract, 
_ over which one may wade when the tide is out. The inner edge 
is much thinner than the outer, being often overhanging, and it 
is flanked by a sloping bank of mud. The surface is of very _ 
uniform height, but quite rough, and interrupted by cracks and 
pools, which teem with marine life. From fractures at the end, it 
is apparent that the hardening has taken place to a depth of sev- 
eral feet below low tide. 
At Gaurapary and Barra Secca, in Espirito Santo, and in their 
vicinity, are several imperfect reef formations, similar to many 
already described; and at the Abrolhos islands, as before stated, 
_ the sand and shingle beaches are often septs consolidated by a 
a cement. 
