236 Scientific Intelligence. 
Il. GroLtoegy AND MINERALOGY. 
1. Geology of the Rio Sao Francisco, Brazil—Mr. QO. A. 
Dersy, of the Brazilian National Museum, has recently been 
making, in company with a party of government engineers, a geo- 
logical examination of the Rio Sio Francisco, from the falls of 
Paulo Affonso, to Januaria. From the latter place Mr. Derby was 
to proceed to Rio de Janeiro overland, by way of the rich mineral 
districts of Minas Geraes. The latest news from Mr. Derby i 
contained in a letter, dated near the city of Barra, on the Sio 
Francisco, November 9, 1879, which gives us a few general state- 
ments of interest, as to the result of his observations up to that 
time. From Paulo Affonso, the ascent of the river for eighty 
leagues was made in canoes, and then a small steamer was pro- 
closing, . peat ing is certain, we have got 
to give up the great Tertiary depression and greatly extend the 
area of the Cretaceous. I that many of the beds, which have 
ing to Professor C. H. Hitcheock.—Professors EpwakpD and C. 
. Hir 
8 led 
note published on page 153 of this volume (and also in the neW 
Report with those works that make the Taconic beds pre-Silurian, 
on Vermont 
geology. In a letter from Professor C. H. Hitchcock, dated 
February 10th, he states that the “ Presumptions” were introduced 
“as a brief exposé of the Taconic System, couched in such 
