546 Brazilian Corals and Coral Reefs. [September, 



above the water its growth is nearly finished, so we can trace its 

 entire history from the beginning to the close. 



The long island of Itaparica, often called the garden of Bahia, 

 fills up almost the entire south-western quarter of the large Bay 

 of Bahia, and contracts its entrance to a width of about five miles. 

 Its outer coast, running obliquely, faces for the most part the open 

 sea, and is at the mercy of its boisterous waves. Skirting the 

 central portion of this coast for a distance of nearly nine miles, 

 is a slightly elevated coral reef, long since abandoned by true 

 living corals and given over to another class of workers, who are 

 putting on the finishing touches and coating it with a hard and 

 durable substance. 



This reef begins directly opposite the city of Bahia, in front of 

 a little rocky point named Jaburu, and stretches away southward, 

 in the general trend of the shore, enclosing behind it a narrow 

 and shallow channel which, at the most, is scarcely one-fourth of 

 a mile in breadth, and generally less. It is most perfect toward 

 the northern end, and has, at irregular intervals, numerous breaks 

 or openings which admit the smaller boats that ply along the 

 shore. Approaching close to Pena, another rocky point about 

 three miles from Jaburu, it ends abruptly; but commencing again 

 just to the south, it runs onward to the Ponte da Cruz, terminating 

 for good on the rocky shore. The study of the geology of the 

 island has shown that the reef follows the submerged, outcropping 

 edges of a series of heavy beds of sandstone, which, at times, 

 bring up on the shore in the form of rocky points. On this solid 

 base the reef appears to have been built, and where, finally, at 

 the south, the sandstone leaves the sea and lies upon the beach, 

 the coral reef ceases to exist. 



The reef is slightly zigzag in its course, and both edges are- 

 very jagged, deeply indented and bordered by projecting or out- 

 lying masses ; but so irregular is every part that it would be quite 

 useless for us to try and describe it accurately. At the northern 

 end it is generally elevated on the outer side and low and level 

 on the inner. The higher portion varies greatly in width and 

 height, and is never flattened on top ; it rises rapidly, often 

 abruptly, from the water, but descends more gradually on the 

 inner side to a level of about one foot above ordinary low tide. 

 From here there extends inward a very flat surface, which is gen- 

 erally quite broad but may narrow down or even nearly disappear. 



