BIRDS OF CUBA II 



that it has been connected with our continent at all, and has only hypothet- 

 ical evidence that the Pre-Tertiary land may have once extended toward 

 the Yucatan peninsula, and that it was only then, if ever, that the Antillean 

 and Cordilleran islands were united." Since Hill's time the fauna, living 

 and extinct, has been much explored, and vertebrate fossils have been 

 found upon Cuba, Haiti and Porto Rico, which indicate a later continental 

 union, and to this view many geologists are now more lenient. In fact 

 Vaughan, a really open-minded person, has quoted Miller saying of the 

 Antillean mammals, especially the hystricine rodents: "They suggest 

 direct descent from such a part of a general South American fauna, probably 

 not less ancient than that of the Miocene, as might have been isolated by 

 a splitting off of the Archipelago from the mainland. Of later influence 

 from the continent there is no trace." To be sure Vaughan has not declared 

 this view definitely supported by the geologic evidence, but he does not 

 on the other hand hold it to be excluded by the geology (cf. 'A Geological 

 Reconnaisance of the Dominican Republic,' Mem. Geol. Surv. of the 

 Dom. Rep., 1921, pp. 1-268, pis. 1-23). I myself have always maintained 

 that there was no question as to the past continental connection, and this 

 view is constantly gaining ground and meeting with less opposition. 



Let us return now to the limestones, which are of particular interest 

 to the zoologist, for it is to their presence that the marvellous development 

 of land mollusks is due, while these areas also support or have given rise 

 by erosion to the soil which supports or formerly supported the rich and 

 varied forest in which the majority of the autochthonous birds live. The 

 limy rocks form a veneer over the old metamorphic base. Their continuity 

 is broadly interrupted by complete erosion over wide areas along the central 

 axial region, and "only the low portion adjacent to sea-level is covered 

 by later deposits" (Hill, 1. c, p. 251). Limestone also caps the summits 

 of the high ranges, often fantastically eroded into mogoies, or outstanding 

 butte-like remnants of larger masses of the rock. De Castro declares the 

 limy deposits to be of Eocene, Aliocene and Pliocene ages, and this view 

 is shared by Hill. 



The two sorts of highlands in Cuba are sharply different from each 

 other. The eminences called sierras or cuchillas, sharp, ragged and steep, 

 are remnants of the old limestone covering carved by erosion. There is 

 some belief expressed that the Sierra Maestra is of a different series from 

 any of the other ranges. My observations are that it is capped with eroded 

 limestone, diente perro (dog-tooth), very similar in character to the other 

 major uplifts. In sharp distinction to the sierras, either wholly of limestone 



