8H The American Geologist. February, ist.7 
"to sa}' that it has been entirely out of our power to finish 
"the work, notwithstanding that the members of the Commis- 
'•sion have worked unceasingly day and night on their hercu- 
"lean task. Neither is the discussion of the material finished, 
"nor are the collections fully determined or arranged. Ev- 
"erything possible has been done, but the work is not ended."* 
His career in Brazil has been summarized by Mr. Rathbun, 
his student, assistant and friend, in these words: "Hartt's 
"greatest achievement in Brazil was probably his solution of 
"the structure of the Amazonian valley. It was founded on 
"the best of palfeontological evidence which proves the exist- 
"ence of an immense pala?ozoic basin lying between the met- 
"amorphic plateau of Guiana on the north, and that of central 
"Brazil on the south, and through which flows the river Am- 
"azonas. Silurian, Devonian and Carboniferous rocks make 
"up the series in regular succession, and in many localities 
"are highly fossiliferous. He has explained the character of 
"the isolated Cretaceous deposits, mostly discovered by him- 
"self, existing along the coast from Para to Bahia, and of the 
"Carboniferous and other regions south of Rio. He has 
"shown us the manner in which the rocky structure of Brazil 
"was built up, and has done much toward solving the rela- 
"tions of the crystalline rocks which compose by far the 
"larger portion of its surface. He has explored the shell- 
■•heaps, burial-mounds, and other relic-localities of prehistoric 
"tribes from far up the Amazonas to the southernmost coast 
"province. We owe to him also the first real satisfactory ex- 
"planation of the reefs of Brazil, which he distinctly shows 
"to be of two kinds — sandstone and coral. He spent much 
"time in studying the customs and languages of the modern 
"Indian tribes of the Amazonas and Bahia, and collected very 
••much material toward a grammar and dictionary of the 
"■Tvipi Indian language in several of its dialects. * * In 
"connection with the Geological Commission of Brazil he 
"founded a large museum in Rio de Janeiro, which will al- 
"ways bear testimony to his great final undertaking."! 
♦Proceedings of the Boston Society of Natural History, vol. xix, pp. 
357-358. 
tSketch of Professor C. F. Hartt, by Richard Rathljun. The Popu- 
lar Science Monthly, June, 1878. 
