AGASSIZ: BAHAMAS. 115 



the former extension of the veneer of coral reef which covered the shore 

 of Cuba during the time of elevation of each terrace ; that is, there 

 probably existed at the time when the older terraces were formed a 

 fringing reef, much like the present elevated fringing reef forming the 

 first terrace, each reef corresponding to its terrace and forming on the 

 sea face of the older underlying limestones a veneer of about the thick- 

 ness of the present " soboruco " reef, say twenty-five to thirty feet. The 

 patches or isolated heads upon the faces of the older limestones are prob- 

 ably the remnant of these successive reefs, the one upon the first terrace 

 being the youngest. The existence of these scattered patches has led 

 many observers to assume that the elevated limestones are of the same 

 age as the elevated reef (the first terrace). 



The sheet of coral, which may have extended to a height of nearly five 

 hundred feet along some parts of the Cuban shore, has been eroded and 

 swept away by the same agencies which have formed the peculiarly 

 shaped limestone hills of the shore line. This erosion has been very 

 extensive ; with the exception of the first terrace, where the coral reef 

 is nearly continuous, it has left only an occasional patch of coral reef or 

 an isolated head here and there, at varying altitudes, to testify to the 

 former existence of the coral reef sheet, the higher inland parts of the 

 reef having all been eroded from the sides of the underlying older ter- 

 tiary rocks. Yet it is strange that no patch of recent reef rock of any 

 extent should have been met with thus far, unless we except the ele- 

 vated reef of Matanzas, where, according to Professor Hill, it reaches 

 a height at least of a hundred feet. 



A similar coral sheet, resting upon oceanic beds and the so called Scot- 

 land beds, has been carefully described by Harrison and Jukes-Browne * 

 as extending at the Barbados from the sea level to nearly eleven hun- 

 dred feet. This sheet consists of a series of " platforms built up one 

 around the other as the island slowly rose from the sea," and this I im- 

 agine to have been the case with the successive elevated reefs of the 

 Cuban coast. The erosion at the Barbados seems to have been much 

 less than along the Cuban coast, leaving the bases of the successive plat- 

 forms of coral reef continuous. According to Browne and Harrison, 2 

 there are six distinct terraces between the sea level and a height of five 

 hundred feet, and between that height and one thousand feet they indi- 



1 The Geology of Barbados, by J. B. Harrison and A. J. Jukes-Browne. Pub- 

 lished by Authority of the Barbadian Legislature, 1890. 



2 The Geology of Barbados, by A. J. Jukes-Browne and J. B. Harrison. Quart. 

 Journ. Geol. Soc., XLVII. 197. 



