1878.] 15 [Rathbun- 
report should properly follow the detailed account of the Devonian 
deposits of the Amazonas, which forms a chapter of considerable 
length in the first unpublished volume of the Geological Commission. 
The death of Professor Hartt has, however, delayed the publication 
of that work for a short time, and it has been deemed advisable to 
issue this report on the fossils at once. It thus becomes necessary to 
describe here in brief the localities where the species treated of in 
this paper were obtained, and the character and relations of the 
rocks in which they were found. 
Prof. Hartt discovered on the Morgan Expedition in 1870 the 
interesting Devonian locality of Ereré, near Monte Alegre, on the 
Amazonas, where he procured the first Devonian fossils found east 
of the Andes in South America. In the following year he revisited 
Ereré, and made large additions to his former collections from there. 
This region he has fully describedin the Bulletin of the Buffalo 
Society of Natural Science, for January, 1874 (pp. 201 to 235), and 
in the same publication (pp. 236-261) I have given descriptions of 
the Devonian Brachiopods obtained by him. In 1876, Mr. Orville A. 
Derby, of the Brazilian Commission, accompanied by Dr. F. José 
de Freitas and Mr. H. H. Smith of the same Commission, reéxam- 
ined the geology of Ereré, and traced the Devonian formation for 
some distance northward of that region, on the Rios Mecurti and 
Curud, finding on each of these two rivers richly fossiliferous sand- 
stones. Passing northward from Ereré, the beds are crossed in de- 
~scending order, so that the deposits of Ereré are newer in age than 
those of the Rios Mecurti and Curua. 
The fossiliferous sandstones of the Rio Curud appear to be identical 
with those on the Mecuru, although the characters of the beds at the 
two places differ slightly; at the former locality they are. fine in 
texture and hard, while at the latter place they are coarse and 
friable. At both of these localities, which are distant from one 
another about twenty-five miles, the fossils are confined to a limited 
*séries of beds. From the Mecurti locality to the Ereré the distance 
is about seventy-five miles, the thickness of the intervening deposits, 
which are largely composed of beds of chert, being in the neigh- 
borhood of one hundred feet. 
At Ereré only three additional species of Brachiopods were found; 
but on the Mecurti and Curud were discovered thirteen species new 
to the Brazilian Devonian fauna, of which three species are identical 
with New York State forms and the remainder, at least in part, new 
