21 



series of Palccozoic fossiliferous rocks, including' the 

 Upper Silurian, Devonian and Carboniferous. The most 

 important discovery was, that the Carboniferous of the 

 lower Tapajos, and that of Maue-assu, extend to the 

 north of the Amazonas, from the Trombetas far to the 

 east of Monte Alegre. This fact is proved to a certaint)^ 

 by the stratigraphy of the beds and by their fossils. The 

 same species of fossils that occur at Itaituba were found 

 on the Trombetas and Curua, in the district of Cujubim, 

 and in Tajury. The existence of a Carboniferous basin 

 on the Amazonas, occupying an immense area, is thus 

 settled beyond doubt ; but the important question, "does 

 it contain coal?" has not yet been answered. The region 

 is generally so covered with a dense vegetation, and so 

 level, that it is next to impossible to find any exposures 

 of rock, except about the falls of the principal tributaries. 

 On the Mcecurii and Curua, to the north of Erer^, was 

 found a rich Devonian fauna, differing onl}^ slightly from 

 that already known from the latter localit}'. The Upper 

 Silurian fossiliferous beds consist of compact flaggy sand- 

 stones, with shaly partings containing ArthropJiycus Har- 

 lani. In the sandstones are found Lingiila cuneata, OrtJiis 

 hybrida, Biicania trilobata, etc. Mr. Derb}' also examined 

 the metamorphic i-egions both to the north and south of 

 the Amazonas, the shell heaps of Taperinha and the 

 mounds of Marajo, and will probably soon publish his 

 results in full. 



The details already given tell but half the story of the 

 field work of the Geological Commission of Brazil. 

 Immense geological, zoological, and ethnological collec- 

 tions had been sent in from all directions, amounting to 

 nearly six hundred cases, which were deposited in a store- 

 house in Rio as fast as they were received. It became 

 necessary to examine and study these collections, so as to 

 supplement and complete the studies made in the field, 

 and a single large room was awarded the Commission for 

 this purpose. The task of opening and arranging this 

 flood of rich material fell mostly upon me, and I soon 

 found that the one room, large as it was, would not prop- 



