112 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
tinent, while the dendritic fjords and islands along the coast from 
Tierra del Fuego to south latitude 41° show that there has also been a 
comparatively recent depression in that region.? A late paper by Pro- 
fessor Gormaz of the University of Chile directs attention to the fact 
that while there are evidences of elevation along that coast, certain 
localities show equally satisfactory evidences of depressions, even within 
the historic period.? 
But the localities mentioned by these writers are far from the region 
with which we have to deal. The question with which we are chiefly 
concerned is whether there have been changes of level within historic or 
geologically recent times along the northeast coast of Brazil, and whether 
such changes, if they did occur, bear directly upon the existence and 
forms of the stone and coral reefs of that region. 
We must also keep in mind the great length of the Brazilian coast-line, 
— about sixty-four hundred kilometres from the northern end at the 
mouth of the Oyapoc on the frontier of French Guyana (5° 10! north 
lat.) to the frontier of Uruguay at the mouth of Rio do Chuy in south 
latitude 33° 45! As in other parts of the world, where so long and so 
nearly straight a coast-line is concerned, the orographic movements over 
this distance have not necessarily been at the same rate or even in the 
same direction. 
The evidence of a geologically recent elevation of the southern coast 
of Brazil is fairly satisfactory, while still further south in the Argentine 
Republic it is remarkably impressive, and considerable elevations are 
reported to have taken place even within the historic period. Many 
facts concerning the southern end of the continent are given by Darwin 
in his “ Geological Observations,” Chapters VIII. and IX.,* and by J. В. 
Hatcher in his paper upon the geology of southern Patagonia These 
facts show that the change of level affected the east coast for a distance 
1 Darwin’s Geological observations, Chap. IX. 
2 Professor Shaler notes, however, that the submarine cutting of ice may be 
responsible to some extent for the form in this case. Bull. Geol. бос. Amer., 1894, 
VI. р. 162. 
3 Francisco Vidal Gormaz. Depressions and elevations of the southern archi- 
pelagoes of Chile. Scottish Geog. Mag., Jan., 1902, p. 14-24. 
* Dr. Friedrich Gustav Hahn published at Leipzig in 1879 a paper upon the 
elevation and depression of coasts. ( Untersuchungen über das Aufsteigen und Sinken 
der Küsten) — in which he gives a brief résumé of the evidence of the upheaval of 
the southern part of Brazil (pp. 98-97). This paper, however, in so far as it relates 
to the coast under consideration, contains only the facts given by other authorities. 
5 J. B. Hatcher. On the geology of southern Patagonia. Amer. Journ. Sci., 
Nov., 1897, CIV., р. 345-350. 
