THE 



AMERICAN NATURALIST. 



Vol. xiii. — SEPTEMBER, 1879. — No. 9. 







BRAZILIAN CORALS AND CORAL REEFS. 



BY RICHARD RATHBUN. 



UR first accurate information regarding the character and 

 extent of the Brazilian coral reefs, as well as of the sandstone 

 reefs, dates from the earlier explorations of the late Prof. Hartt 

 in Brazil. Prior to the publication of his general work, referred 

 to in the June number of this journal, there existed only a few 

 imperfect notices of corals and coral banks on the Brazilian 

 coast. Spix and Von Martius, during their South American 

 travels in the early part of this century, discovered patches of 

 living and dead corals at several localities along the sea coast of 

 Bahia, but they did not stop to fully investigate them or extend 

 their observations, and the corals they collected were erroneously 

 referred to old Lamarckian species. 



Darwin, who touched at the Abrolhos islands, saw corals grow- 

 ing upon the shore, but overlooked the vast and curious reefs 

 that occupy so much of the surrounding region. On the author- 

 ity of others, however, he states that around these islands " the 

 bottom of the sea is entirely coated by irregular masses of corals, 

 which, although often of large size, do not reach the surface and 

 form proper reefs." In this he was partly right, but very largely 

 wrong, as we shall see farther on. Darwin also refers to coral 

 reefs at Maceio and Pernambuco, and Prof. Dana mentions a reef 

 near the latter place. Other observers had increased the number 

 of localities where coral reefs occur, so that when Prof. Hartt 

 began his studies of these structures, we were already acquainted, 

 in a general way, with a line of scattered, and often widely sepa- 

 rated, coral reefs and banks extending from the Abrolhos islands 

 northward to Maranhao. Our information respecting them was, 



VOL. XIII. — NO. IX. 37 



