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 to 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 Pontes, 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 gi'een, 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 Leitao 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, Eimicea sulphurea, grows 

 upon the inside of the reef along its entire length. It is especially 

 abundant near the Barreta do Leitao, where there are also many fine 

 specimens of PlexaureUa. 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 On^a the reef is higher, and its 

 surface much harder than it is near the lighthouse. Below the Barreta 

 da On5a 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 nuUipores, 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 



