MUSEUM OF COMPARATIVE ZOOLOGY. 285 



bed of coal on which the mine is worked dips to eastward, and is about 

 three feet in thickness. Smaller beds have been traced as outcrops to 

 the westward of the Yampopata mine ; the same bed has also been 

 opened on the east coast of the peninsula of Copacabana. Near Vilque 

 quite a number of coal-beds are found, in one of which a small pit has 

 been opened and coal of an excellent quality discovered. The bed dips 

 to the west. At Santa Lucia three small beds have been tested, and 

 considerable prospecting without satisfactory results has been done 

 on some of the beds. The coal appears of a rather purer quality, 

 but is mixed with layers of shale. At Sumbay, though there has not 

 been much mining done, the facilities for mining are good. Several 

 beds have been tested to a considerable depth (90 feet), and a good 

 quality of coal developed. As the mines are only about two miles 

 from the railroad, the position is, from its excellent grade to the road, 

 admirable. The railroad from Sumbay to Puno runs directly across 

 the width of the Carboniferous system of the elevated plateau to 

 the west of Lake Titicaca, and the nature of the successive basins, 

 all running more or less northwest and southeast, can readily be 

 traced. Although my observations show a far greater extent of 

 the Carboniferous series than was supposed to exist, it is evident 

 from information gathered in the country that its northern terminus 

 is by no means ascertained. Colonel Flint 'informs me that in the 

 Cuzco Valley along the railroad from Juliaca to Cuzco there are 

 beds of coal identical with those I had the opportunity to visit. Mr. 

 J. J. Thomson, on his map of the Department of Puno, marks the 

 district to the west of Pomata as Carboniferous. Mr. Orrego, in a 

 sketch of the minerals occurring in the Departments of Arequipa and 

 Puno, mentions also as Carboniferous the localities which I visited 

 along the line of the Arequipa and Puno Ptailroad. Mr. Orrego also 

 states that this Carboniferous system extends as far north as Caylloma. 

 He subsequently mentioned to me that they form a series of basins 

 having the same general structure and position relatively to inter- 

 calated metamorphic rocks noticed above, which at the points of con- 

 tact have highly metamorphosed the shales and sandstones in the 

 vicinity. Professor James Orton has also found, in the extension of 

 the same general line as the axis of Lake Titicaca, Carboniferous 

 fossils at the head-waters of the Amazonas (Pichis River), while he 



