128 Mammalia of Southern Brazil. 
A large part of the North American strata which have been by 
various authors referred to the Permian have no valid claim to be 
either so considered, or as being separate from the upper Coal- 
measures. But a part of them may be reasonably assumed to be 
homotaxially equivalent with at least a part of the European Per- 
mian ; although their delimitation from the Coal-measures may in 
most cases be difficult or impracticable. 
The evidence upon which the Texan strata have been referred 
to the Permian is fuller than that which has been adduced with re- 
gard to any other North American strata, that have been so re- 
ferred. That is, the evidence of both vertebrate and invertebrate 
fossils is in favor of such reference, and the difference in the char- 
acter of the strata from those of the underlying Coal-measures, al- 
though not great, is conveniently distinguishable. Still, it is true 
that the Texan Permian strata bear many Coal-measure invertebrate 
species ; and its flora is at present unknown. 
ON THE MAMMALIA OBTAINED BY 
THE NATURALIST EXPLORING EXPEDITION 
TO SOUTHERN BRAZIL. 
BY E. D. COPE. 
THE Naturalist Exploring Expedition left New York for South- 
ern Brazil in the year 1882, and landed at Porto Alegre in 
the department of Rio Grande do Sul, with the object of making 
collections in that province.^ It was under direction of Herbert H- 
Smith, whose former service under Prof. Frederick Hartt in the 
Geological Survey of Brazil, had given him ample acquaintance with 
the people and language. Regular collections were first made at 
the village of Sao Joao do Monte Negro, on a tributary of the Ura- 
1 Articles descriptive of this region by Mr. H. H. Smith will be found in the 
Naturalist. 1883, pp. 480, 707 & 1007. 
