ne 
bergs dropping large granite boulders from the same into the muddy 
sediments farther south, on the African continent, may have had 
its parallelin South Brazil from Minas Geraes to Rio Grande do Sul. 
Certainly true glacial action has been proven to have taken place 
in South Africa at the beginning of Permo-Carboniferous time, and as 
the same succession of rocks occurs at practically the same latitude 
(25°-35° South) in South Brazil, the presumption is all in favor of 
the glacial hypothesis to account for the Rio Negro deposits, as well 
as for the facetted pebbles collected by Dr. Lisboa in Minas Geraes. 
With this view of the matter, Agassiz and [lartt were right in 
asserting that there had been a Glacial epoch ‘in Brazil, but it 
was during the closing period of Carboniferous time instead of during 
the Pleistocene. The occurence of Glacial phenomena during Permian 
time in Europe upon which some geologists have insisted, may have 
been contemporaneous with the same conditions south from the 
equator. 
The writer had little time to devote to these interesting problems, 
and only mentions them here in order to stimulate inquiry and 
research by other investigators. 
General Topographic and Drainage Features 
The general topography of South Brazil may be briefly sketched 
in a few words as follows: The Serra do Mar, a high range of 
mountains composed mostly of granite and gneissoid rocks, frequently 
cut with dikes of old eruptives, and often enwrapping ancient sedi- 
mentary beds of Cambrian or pre-Cambrian age, rises abruptly from 
the sea in the region of Rio de Janeiro and trending southward 
parallel with.the Atlantic shore line, only a few miles distant 
therefrom, makes the outer rim of the great plateau region. 
This mountain mass, the general elevation of which is about 1000 
meters, extends southward through S. Paulo, Parana, and Santa Ca- 
tharina dying down rapidly southward from Florianopolis, and practi- 
cally disappearing from view beneath the sea before reaching the border 
of Rio Grande do Sul;in fact the trend of the granitic mass appears 
to carry it out seaward where it disappears gradually either by the 
general south-west subsidence, or by faulting, while the sea has 
nearly completed the removal of all but the higher peaks like Cochilha 
