[50] For a list of the fossils that form the basis of the age determinations in this chapter see [Appendix B].
[51] Eastern Bolivia and the Gran Chaco, Proc. Royal Geogr. Soc., Vol. 3, 1881, pp. 401-420.
[52] The Physiography of the Central Andes, Am. Journ. Sci., Vol. 28, 1909, p. 395.
[53] See paper by H. S. Palmer, my assistant on the Expedition to the Central Andes, 1913, entitled: Geological Notes on the Andes of Northwestern Argentina, Am. Journ. Sci., Vol. 38, 1914, pp. 309-330.
[54] The best photograph of this condition which I have yet seen is in W. Sievers, Südund Mittelamerika, second ed., 1914, Plate 15, p. 358.
[55] Paschinger, Die Schneegrenze in verschiedenen Klimaten. Peter. Mitt. Erganz’heft, Nr. 173. 1912, pp. 92-93.
[56] Hann, Handbook of Climatology, Part 1, trans. by Ward, 1903, p. 232.
[57] S. I. Bailey, Peruvian Meteorology, 1888-1890. Ann. Astron. Observ. of Harvard Coll., Vol. 39, Pt. I, 1899, pp. 1-3.
[58] F. E. Matthes, Glacial Sculpture of the Bighorn Mountains, Wyoming, Twentieth Ann. Rept. U. S. Geol. Surv., 1899-1900, Pt. 2, p. 181.
[59] Idem, p. 190.