396 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1908. 



tensive collection of fossils from the Silurian and Devonian of 

 Bolivia made by Steinmann. Inasmuch as the same faunas probably 

 extend into Peru the descriptions of the fossils will be of value when 

 similar studies are undertaken farther northward. Recently Dereims 

 (1906) has described the occurrence of the Silurian at many places 

 in Bolivia, some of which are near the border of Peru in the Titicaca 

 basin, although most of them are to the south in the Cordillera Real 

 (Oriental) of Bolivia, but he has not yet described his collections of 

 fossils. 



DEVONIAN. 



The first recognition of a Devonian locality which has a bearing 

 on the geology of Peru was by d'Orbigny (1842), who made collec- 

 tions in the Titicaca Lake region in Bolivia and found fossils which 

 he described as characteristic of that period. 



Forbes (1861) when in the field did not distinguish the Devonian, 

 but included it with the upper Silurian. Later he was induced by 

 Salter, who studied the collections of fossils, to show the Devonian 

 in his section because of the finding of Phacojys latifrons^ which is 

 admitted to be a truly Devonian species. Forbes's localities are in 

 Bolivia, near Lake Titicaca. 



Mention has already been made of the collections from Bolivia 

 made by Steinmann which were studied by A. Ulrich (1892) and 

 found to contain an interesting series of Silurian and Devonian 

 fossils. The descriptions by Ulrich will be of value when the Devo- 

 nian in adjacent parts of Peru receives critical study. 



Still later Dereims (1906) has described the occurrence of the 

 Devonian in Bolivia, near Lake Titicaca. He says it consists of sand- 

 stones of different colors and thicknesses, alternating with shales of 

 less importance. He obtained a collection of fossils, some of which 

 he mentions, but he has not yet published his paleontologic studies. 



All the foregoing literature pertains to Bolivia, but it has a direct 

 bearing on the geology of Peru, since the Devonian undoubtedly ex- 

 tends across the border in the Titicaca basin. Thus far no Devonian 

 fossils have been described from Peru, but Duenas ° (1907) obtained 

 fossils from Taraco northwest of Lake Titicaca which Bravo 

 has reported to be Devonian, although he did not determine them 

 specifically. 



CARBONIFEROUS. 



The Carboniferous in Bolivia was studied by d'Orbigny (1848), 

 who described a number of fossils. This was the first information 

 which gave a definite reason to suppose that the Carboniferous exists 



« Enrique I. Duenas, Bol. del Cuerpo de Ingenieros de Minas del Peru No. 53, 

 p. 156. See footnote. 



