742 CHARLES SCHUCHERT 



diabase and porphyry, giving rise to hornstones and dark limestones 

 with the fossils transformed into silicious pseudomorphs. 



Much of this fauna remains unworked. Some of the leading 

 fossils are: Lophophyllum near proliferum, Lonsdaleia rudis, Rhipi- 

 domella penniana, Orthotichia morganiana, Schuchertella tapajo- 

 tensis, Streptorhynchus hallianus, Orthotetes correana, Chonetes glaber, 

 Strophalosia cornelliana^ Productus semireticulatus, P. lineatus, P. 

 cora and seven other species, Spirifer cameratus, S. condor, S. rocky- 

 montanus, Spiriferina transversa, S. spinosa, Reticularia perplexa, 

 Ambocoelia planoconvexa, Hustedia mormoni, Seminula argentea, 

 Cleiothyris royssii, Aviculopeden occidentalis , A. herzeri, Lima retifera, 

 Pinna per acuta, Myalina kansasensis, Allorisma subcuneata, Platy- 

 ceras nehrascensis, Pleurotomaria speciosa, Euphemus carbonarius, 

 Bellerophon crassus. (For a complete list, see Katzer, pp. 162-67.) 



Another well-known area for Carbonic is that of the Trombetas. 

 The observed thickness is a little over 6"^. The fauna here is a 

 smaller one (seventeen species) than that of the Tapajos (115 species), 

 but the species are the same in both areas. 



Katzer regards the Tapajos faunas as highest Upper Carbonic, 

 and not of Lower Permic age as did Waagen. Derby (6: 173) states: 



The fauna shows the closest relationship to that of the Coal Measures of the 

 Western States, more than half of the species being identical. I have already shown 

 that the Bolivian and Peruvian Carboniferous faunas, as far as they are known, are 

 equivalent to the Brazilian, and to that of the North American Coal Measures. 



To the north of the Amazon River the Carbonic is known along the 

 river Curua and in the region north of Alemquer (Katzer). It con- 

 sists here of sandstones and gray sandy- calcareous shales with a 

 thickness estimated at 200™. The fauna obtained here Derby regards 

 as of the same age as that of the Tapajos. 



Of all the Palaeozoic deposits of the Amazonas, those of the Carboniferous 

 occupy the most extensive area and, at the same time, present the greatest diffi- 

 culties to study. Composed for the most part of soft beds, they suffered extensive 

 denudation, during the interval between the close of the Carboniferous and the 

 beginning of the Tertiary, during which time they were, for the most part, exposed 



above the level of the sea Mr Smith, who has best studied these deposits, 



is of the opinion that their total thickness is not less than 2,oco feet, and, although 

 the data for the calculation is very defective, I cannot .-ay that it is exaggerated 

 (Derby, 6:171). 



