BRANNER: THE STONE REEFS OF BRAZIL. 199 
Venus) which are as fresh and bright as the shells upon the present 
beach." These bivalves are much sought for as food. They are taken 
in the bays behind the reefs and near the shores, and also on sandbars. 
Their dead shells are abundant on the present beaches. 
The Venus, so abundant in these rocks, lives in the sand; but the 
animals stand on end about five centimetres below the surface, and the 
living shells are covered with horny epidermis. The shells found in 
the rocks are always, so far as I have yet seen, without epidermis, the 
valves are apart, and the shells usually have the convex side upward. 
These facts show that the shells, as they occur in the rock, are not in 
the places where the animals lived. 
Several other shells, mostly gasteropods, are found in the rocks of the 
stone reefs, but without exception they are forms that are often found 
dead on the beach, or living in the shallow water near shore. 
The littoral character of the shells found in the reef rock should not 
be overlooked, for Liais thinks some of the reef beds were formed at sea 
(“formé au milieu de la mer”), and that they have been displaced since 
then.? 
Baräo de Capanema speaks of seeing fragments of pottery imbedded 
in the rock near the lighthouse at Bahia. 
Hartt thinks Pissis and Darwin “ in all probability ” mistook the stone 
reefs for Tertiary rocks. This seems to be an unwarranted assumption, 
for in Pissis’s paper there is no specific mention of the reef rocks, while 
Darwin, in his paper on the Pernambuco reef, assigns to them a recent 
date. 
Although one gets the impression that the fossils of the stone reefs are 
all recent, the fact should not be overlooked that these fossils have 
never been systematically studied in connection with the existing fauna. 
Moreover, the reefs one sees, and to which access is easiest, are all the 
new outer reefs, and usually the latest ones formed, while the old reefs 
are to the landward, and usually near the bases of the hills that formed 
the old shore lines. 
1 One sometimes hears the suggestion that the fresh colors of the reef fossils 
is evidence of the recent age of the sandstone reefs, This may be true to some 
extent, but these colors alone could not be accepted as evidence. We have rocks 
of Jurassic age even, whose fossils still preserve their bright colors, 
2 L'Espace Céleste, р. 545, 548. 
8 Trabalhos da Commissão Scientifica de Exploração. Rio de Janeiro, 1865. 
Introducção, I., p. CXXXVII. 
4 Geol. and Phys. Geog., р. 269. 
5 Mém, Inst. France, 1842, X., p. 398. , 
