BRANNER: THE STONE REEFS OF BRAZIL. 221 
3° 51’ 271; longitude 33° 48’ 57” west of Greenwich. “The reef ex- 
tends about one and one-fourth miles in latitude and nearly one and 
three-fourths miles in longitude and is covered at high water with the 
exception of Sand and Grass islands on the west and the scattered rocks 
on the south and east sides. These objects are from ten to fifteen feet 
above the reef, which is formed of coral, generally level, though with 
many holes in it. . . . We found coral bottom at fifteen fathoms, six 
miles east of the reef, but no bottom at thirty fathoms, two and one-half 
miles north-northeast, nor at seventy fathoms four miles southwest of it. 
The tide rises about five feet.” (See page 82 of that work.) 
Certain points are marked on Lieutenant Lee's chart as black rocks 
amid the coral reefs, suggesting that the reef may rest upon a base of 
eruptive rocks." Findlay? has the following: “The Rocas. This low 
coral reef is perhaps the most formidable danger in the Atlantic. It is 
the only one of its character in that ocean — a true atoll isolated from 
all the surrounding lands, so many of which are found in the Pacific.” 
This author quotes as follows from a report of a visit by Commander 
Parish made in 1856. Не “obtained coral bottom in thirteen fathoms,” 
before the island was sighted, and again he “anchored in twenty 
fathoms,” before the island was sighted, and again he “anchored in 
twenty fathoms, coral bottom, at about two and one-half miles from 
the shore.” 
In 1857, Captain J. Н. Selwyn, В. N., resurveyed the Rocas and 
wrote of it then: “It is a perfect coral island, circular, about two 
miles in diameter, and has in its centre a shallow lake with an opening 
to the sea. The greater part of the reef is under water. There are two 
sand banks, one on the southwest side, and the other on the northwest 
side of the island. These are ten or twelve feet above water at all tides, 
and are two hundred or three hundred yards long. The smaller has on 
it some stunted vegetation and hazel trees." Reclus speaks of the Rocas 
as a “veritable atoll of coral like those of the Indian Ocean, enclosing a 
lagoon about ten kilometres in circumference.” “a 
There is also a valuable article upon the Rocas published anonymously 
in the * Mercantile Marine Magazine." * 
1 Dr. J. В. Regueira Costa, of Pernambuco, has kindly obtained for me speci- 
mens of the black rocks of Rocas, but up to the time this report goes to press they 
have not been received. 
2 Findlay, Alexander George. A sailing directory for the Ethiopic or South 
Atlantic Ocean. 9th ed. London, 1888, p. 227-281. 
8 É. Reclus. Nouvelle géographie universelle. XIX. Amérique du Sud, 
p. 223. Paris, 1894. 
4 Mercantile Marine Magazine, XIII., p. 88-50; 65-80; 141-143. London, 1866. 
