14 BULLETIN : MUSEUM OF COMPAKATIVE ZOOLOGY. 



which he says there are Tertiary and Cretaceous rocks in the region, and 

 he seems to mean that the upper colored beds somewhat resembling 

 the New Red Sandstone of England are Tertiary, and that the impure 

 limestones beneath them are Cretaceous. He mentions no fossils, how- 

 ever, and gives no reason for calling either of the series by these names. 



In 1865, Prof. Louis Agassiz touched at Parahyba do Norte, and 

 Hartt states that he found there fossil estherians from which he (Hartt) 

 infers that the deposits are of fresh-water origin and equivalent to the 

 Bahia beds which he regarded as of Cretaceous age.^ This, however, 

 was not published until 1870. 



Later Hartt set off from the beds later accepted as Cretaceous an 

 upper and apparently a well-differentiated series of highly colored and 

 mottled beds, and called them Tertiary. This scheme first appeared in 

 1868,^ but was treated more fully in his book that appeared in 1870,^ 

 and again in a paper read before the American Geographical Society in 

 187L* 



This designation of the colored beds, afterwards known as the Ter- 

 tiary, commended itself so favorably to field geologists in Brazil that it 

 was immediately accepted,^ though Hartt himself observed afterwards 

 that " one may find variegated clays on the Amazonas containing Devon- 

 ian and Carboniferous fossils.® And yet no one ever succeeded in all the 

 thousands of kilometres of exposure in finding a single well-defined line 

 of division between the Cretaceous and the supposed Tertiary beds,'' and 

 no one found a fossil in the so-called Tertiary ones, with the possible 

 exception of the fossil plants found within the last few years in the State 

 of Bahia, the age of which has not yet been determined. But aside 

 from these two important wants, the assignment of the horizontal colored 

 upper beds to the Tertiary appeared to be a proper one, and no especial 



1 Geology and physical geography of Brazil, p. 445. 



2 C. F. Hartt. Resume of a lecture on the growth of the South American con- 

 tinent, p. 5. Reprinted from the Cornell Era of Dec. 12, 1868. Ithaca, N. Y., 1868. 



3 C. F. Hartt. Geology and Physical Geography of Brazil, p. 557. Boston, 

 1870. 



* Ann. Rep. Amer. Geogr. Soc. Vol. IIL, p. 231-252. 



5 The present writer published in 1889 a paper upon the Cretaceous and Ter- 

 tiary geology of the Sergipe-Alagoas Basin of Brazil. (Trans. Amer. Phil. Soc, 

 XVI., p. 369-434) in which he followed Hartt's division. 



6 Amer. Journ. Sci. 1872. CIV., p. 57. 



" Both Hartt and Williamson say the Tertiary overlies the Cretaceous uncon- 

 formably. Geol. and Phys. Geogr. of Brazil, 557; Resume of a lecture on the 

 growth of the South American continent (Ithaca, N. Y., 1868), p. 5. Trans. Man- 

 chester Geol. Soc, 1866-67. VI., p. 114. 



