AGASSIZ : BAHAMAS. 109 



elevated terraces, though originally applied only to the elevated coral 

 reef forming the first terrace. These terraces are striking features on 

 certain reaches of the coast, and are so noted in the descriptions of the 

 coast pilots that they often serve to distinguish special points. 



During my trip along the north coast of Cuba I became satisfied that 

 I had misinterpreted the nature of the elevated terraced limestones of 

 the shores of the island. With other naturalists, I had been led to 

 think from a first examination, made many years ago, that these elevated 

 limestones were coral reef rock limestones representing coral reefs of per- 

 haps twelve to fifteen hundred feet in thickness. The true character of 

 the coral reef rock, which has in general been elevated to a height of not 

 more than twenty-five or thirty feet, is readily made out. The exposed 

 surface of the platform of the first terrace is often one mass of coral heads, 

 and it requires but little effort to reconstruct this into a recent living 

 reef. "When we come, however, to the flats of the second and third ter- 

 races, the problem is not so simple. It is evident that the limestones 

 are of older age than those of the raised coral reefs flanking the shores. 

 They underlie the elevated reefs, and, while greatly altered, yet contain 

 an occasional mass of coral belonging to the reef-building species, but so 

 few in number that we can hardly call the stone of which they form a part 

 a coral reef limestone. These questions were brought to mind vividly at 

 Santiago, while exploring the limestone terraces; also at Saboney, at 

 Baracoa, where the thickness of the elevated reef is not more than thirty- 

 five feet, at Banes, at Matanzas, and at Havana. It became important 

 to determine exactly the age of the limestones forming the second, third, 

 and higher terraces, and to ascertain how far the presence in older lime- 

 stones of an occasional mass of a species of reef-building coral, at different 

 heights all the way up to two hundred and fifty or even to over four hun- 

 dred feet from the level of the first terrace, justified the conclusion that 

 these deposits of older limestones belong to the group of coral reef lime- 

 stones. Such an inference from the presence of a few corals in the older 

 limestones seems to me no more reasonable than to speak of a few iso- 

 lated heads of reef-building species found along the shore lines of any 

 coast or island as constituting a recent coral reef. 



My observations are here given as noted during the cruise of the 

 " Wild Duck." Not having myself the time to make the necessary ex- 

 plorations, I gladly accepted the proposition of Professor Robert T. Hill, 

 of the United States Geological Survey, to carry on this exploration, and 

 to determine the character of the elevated terraced limestones, and their 

 relation to the overlaying elevated coral reef, as well as the greatest alti- 



