324 The American Geologist. November, i904. 
As to the age of these beaclies, they seem to be interbedded 
only with PHocene and recent rocks, although they are bttilt 
against rocks of all ages. It is therefore inferred that the 
formation of the stone reefs began in early Pliocene times, 
and that it has continued to the present. 
It is' probable, therefore, that the Brazilian coast h'as been 
extended eastward by this process of land-making and that it 
will continue to be extended until some geological revolution 
diverts or destroys the equatorial current. That branch of 
this current which passes northwestward becomes so diluted 
by the fresh waters of the Amazon that its mineral solutions 
are carried on and do not serve to cement the Ijeach sands. 
The same change takes place, doubtless, in the waters of the 
southern branch of this current, by reason of the greater and 
freer drainage from the land in reaching the southern sub- 
tropical and temperate latitudes. In the tropics, as' in the 
Levant, the surface waters are largely evaporated before 
reaching the ocean. 
The volume is accompanied by numerous plates, taken 
from photographs reproduced in the excellent style for which 
the Museum of Comparative Zoolog}- is known, and by hydro- 
graphic charts from the Brazilian surve^-s and original surveys 
bv the author and his assistants. x. h. w. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
The Geology of the JVafkiiis and FJinira Quadrangles accompanied by 
a Geologic Map; bulletin N. Y. State Museum 8i, 1904: John M. 
Clarke and D. Dana Luther. 
The Watkins and Elniira quadrangles lie to the east of the Canin- 
daigua-Naples sheet which has but recent)}' been issued and the work 
now published has been carried out as a continuation of the fbrmer 
areal mapping. An interval between the two sheets is now in process 
of survey. As in the former work the large scale of the map has been 
made use of in delineating the variations in the formations with great 
exactitude, since experience has shown that in the terranes under in- 
vestigation a reliable basis of discrimination of such refined sub- 
divisions as the authors have arrived at can lie found alone neither 
in geologic nor in paleontologic data. 
