BRANNER: THE STONE REEFS OF BRAZIL. 233 
the seaward side, and slopes gradually from its outer or eastern margin 
inward toward the channel. . The channel on the landward side of the 
reef is a shallow one, being only two metres deep at low tide toward the 
upper end ; there are also a few deeper pools behind the reef near its lower 
end. The reef at its northern end, near the lighthouse, is low — only a 
few points being a foot out of water at the lowest tide. At the northern 
end the top of the landward side of the reef is comparatively smooth, 
while the outer or seaward side is exceedingly rough and difficult to 
walk over. The points of the calcareous growths are too sharp to be 
Stepped upon, and too weak to sustain a man’s weight, so that when 
one tries to walk over them he breaks through and sinks to his ankles 
or te his knees, and gets his legs and feet twisted and bruised. There 
are no large corals on the northern part of the reef; the only genus 
common is Porites, and of this the specimens are small and insignificant. 
The higher parts of the rocks are overgrown by brown polyps which 
grow in large patches, and by green, grape-like clusters of seaweeds. 
These polyps and seaweeds are found the whole length of the reef. 
Following the reef toward the south, its landward side has the bottom 
in places covered with sea-urchins, in others with seaweeds or with sand. 
Here or there the inner or land side of the reef has a few Milleporae, 
Porites, and Favia, though the specimens are all small. Along the 
inside near the Barreta do Leitäo in the shallow water is a great number 
of small red starfishes, of which specimens were collected. Large 
quantities of the small, yellow, branching coral, Eunicea sulphurea, grows 
upon the inside of the reef along its entire length. It is especially 
abundant near the Barreta do Leitäo, where there are also many fine 
Specimens of Plexaurella. The chief collections made on this part of 
the reef were of the corals first mentioned, starfishes, small crabs, and a 
few gasteropods. Near the Barreta da Onga the reef is higher, and its 
Surface much harder than it is near the lighthouse. Below the Barreta 
da Onga the surface of the reef is covered with reddish-brown sand, and 
this continues to nearly opposite the southern extremity of this section 
of the reef, At the lower end of this section of the reef the sand is 
about one metre deep. The barrier—the reef with its covering of 
Band — continues to increase in height as the south end is approached, 
the highest parts projecting nearly or quite one metre and a third above 
the water at extreme low tide. On the outer part of the rocks are 
Many Bryozoa and nullipores, but, owing to the ragged surface and the 
breakers that dash upon it, collecting them is difficult and dangerous 
even in a sea more than ordinarily calm. The shell of calcareous 
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