SUMMARY. 93 



is shown by the involved Matanzas limestones, which were eroded from 

 the valley before the elevation of the closing barrier. This movement 

 turned the valley into a lake-basin until it could be drained by making 

 its new outlet. The time of the formation of the canyon was the same 

 as that of all the gorges along the coast, or, as has been shown in the case 

 of Xagua bay, since the Zapata epoch ; that is, since middle Pleistocene 

 days. 



Caverns. , 



The limestones of Cuba are frequently very much perforated by caverns. 

 The rocks are often completely honeycombed upon their surfaces by rains 

 alone, as at Trinidad. Some strata are more cavernous than others, but 

 none are exempt from the solvent powers of the tropical rains. Some 

 of the caves descend below sealevel. Many of the caves are large, and 

 some of them have formed retreats for animals, and even man, as some 

 flints and pottery were found by the writer in a cave at about 350 feet 

 above the sea at Trinidad. There were also a number of shells which 

 had been washed into the red, cave earth (not derived from the walls of 

 caverns) during some recent subsidence, or else have been carried there 

 for human food, which latter is suggested, as the shells are mostly broken . 

 The species were kindly determined for me by Mr Charles T. Simpson 



Melongena melongena, Lin. Area noae, Lin. 



Livona pica, Gm. Lucinajamalcensis,J^am.^k. 



Stroinbus gigas, Lin. Mytilus hamatus, Say. 

 Area aurieula, Lam'k. 



In the same cave Mr Frank M. Chapman found bones of an extinct 

 Capromys {Hiitia). The cave is now tenanted by bats. 



Summary. 



This paper treats of the geological history of Cuba primarily from the 

 geomorphic standpoint, as recorded in the great valleys of erosion during 

 the Pliocene and Pleistocene periods, and their extension into the deep 

 fiords. These physical changes are summarized in the form of the fol- 

 lowing table. While the paper was mostly written as a preface to the 

 '' Reconstruction of the Antillian Continent," it was not ready for pub- 

 lication until afterwards, hence the comparison between the geology 

 of Cuba and that of other islands of the West Indies, and also the char- 

 acter of the fauna of the island, have been considered in the paper already 

 named. 



