ANNOTATIONS AND ADDITIONS. 69 



Western Coast of America, are entirely without coral reefs, 

 although so near to the many Atolls of the Low Islands, 

 and the Archipelago of the Marquesas. This absence of 

 corals might perhaps be ascribed to the presence of colder 

 water, since we know that the coasts of Chili and Peru 

 are washed by a cold current coming from the south and 

 turning to the westward off Punta Parina, the temperature 

 of which I found, in 1802, to be only 12.5 Reaumur 

 (60.2 Pah.), while the undisturbed adjacent masses of 

 water were from 22 to 23 Reaumur (81.5 to 83.8 Pah.) ; 

 and there are also among the Galapagos small currents run- 

 ning between the islands, having a temperature of only 

 11.7 Reaumur (58.2 Pah.) But these lower temperatures 

 do not extend farther to the north along the shores of the 

 Pacific, and are not found upon the coasts of Guayaquil, 

 Guatimala, and Mexico ; nor does a low temperature pre- 

 vail at the Cape de Verd Islands on the "West Coast of 

 Africa, or at the small islands of St. Paul (St. Paul's rocks), 

 or at St. Helena, Ascension, or San Pernando Noronha, 

 which yet are all without cora reefs. 



While this absence of coral reefs appears to characterise 

 the western coasts of Africa, America, and Australia, on 

 the other hand such reefs abound on the eastern coasts of 

 tropical America, of Africa, on the coasts of Zanzibar and 

 Australia, and on that of New South Wales. The coral 

 banks which I have chiefly had opportunities of observing 

 are those of the interior of the Gulf of Mexico, 'and those to 

 the south of the Island of Cuba, in what are called the 

 " Gardens of the King and Queen" (Jardines y Jardinillos 



