REVIEWS 975 



and that, until the trashy jjortion of the evidence is purged away and 

 solid data are produced, no conclusions can safely be drawn. 



These specific criticisms, which have required some little fullness 

 of statement, give disproportion to this review, and it needs correc- 

 tion by a reaffirmation of the very high excellence of the work as a 

 whole. T. C. Chamberlin. 



The Oldest Fossiliferous Beds of the Amazon Region. By Friederich 

 Katzer, chief of the geological section of the Para Museum. 

 Boletim do Museu Paraense, Vol. I, No. 4, pp. 436-43S. Para, 

 Brazil, 1896. 



It has already been satisfactorily shown that of the Paleozoic series 

 we have in the Amazon valley rocks of Silurian, Devonian, and Car- 

 boniferous ages. Whether there is any Cambrian and Permian 

 remains to be determined. The beds below the knowm Paljeozoic 

 rocks are gneisses, crystalline-schists, etc., referred to the Archsean. 

 It is not impossible that some of the quartzites and mica-schists are 

 Cambrian and Lower Silurian. 



Upper Silurian beds have been recognized in the Amazon region 

 thus far only at one place, mainly on the Rio Trombetas at Viramundo 

 Falls, where fossils have been found. 



In 1895, however, Dr. Joao Coelho made on the Rio Maecuru a 

 rich collection which has been presented to the Para Museum. After a 

 careful examination of these rocks, graptolites have been found in 

 them, thus proving the existence of Upper Silurian rocks in the 

 Maecuru valley. This is the first discovery of these fossils in Brazil. 



It is worthy of mention, also, that these graptolites were found in 

 beds composed principally of siliceous spicules of sponges. These 

 spicules are visible to the naked eye, but they are better seen with a 

 lens magnifying ten to twenty diameters, or in thin microscopic sec- 

 tions. These sponge remains are the first of the kind found either in 

 the Amazon region or in the Palaeozoic beds of Brazil. 



The author has recently presented a memoir on the geology of the 

 Amazon, and especially on the Archaean rocks, to the Academy of 

 Bohemia, based on his studies of a series of specimens from the zone 

 north of Alemquer, and of another set brought by Dr. Goeldi from 

 his scientific expedition to Guiana in 1895. In an early number of 

 this Boletim he will give a resume of that paper. 



