MUSEUM OF COMPARATIVE ZOOLOGY. 259 



to the genesis of the island. Its sliape and outline have been described 

 by various writers, notably Humboldt, Sagra, and Reclus, and I shall 

 touch upon only those details or generalities that will help to elucidate 

 its geologic history. 



The outline of the island might be compared to that of a hammer- 

 headed shark, the head of which is the culminating range along the 

 straight Santiago coast, from which extends westward the longer, lower, 

 and more sinuous mass of the islaiid, while the fins are represented by 

 pendant coral reef archipelagos. The Santiago coast is excessively 

 mountainous, and is supposed to be in some way genetically connected 

 witli the mountain systems of the other Antilles. Concerning the com- 

 position, age, and topography of these ranges, we know little excejit 

 what has been told by other writers, to the effect that they extend 

 aproximately in an east and west direction, towering far above the 

 levels of the remaining purtion of the island, and occupy a very narrow 

 strip close to the ocean's margin. Extending away to the north and 

 west from this nucleul elevation is the main body of Cuba, which is 

 primarily a great limestone plateau intensely eroded and terraced, with- 

 out any well defined axis of higher elevation except as indicated by the 

 headwater drainage that diverges from it and flows into tlie opposing 

 seas, the latter feature corresponding to the longitudinal axis of the 

 island. The highest elevations do not occur in a continuous ridge, but 

 are irregularly dispersed, as if they were remnaiits of a dissected elevated 

 plateau, diversified by plains and irregular chains of hills, often nearei 

 the margin than the centre, and seldom over two thousand feet in 

 altitude. 



The topographic forms belong to two categories, those of the inland 

 and tliose of the coast. The former depend upon uplift and erosion, and 

 are mostly the product of superficial agencies. The coastal featiires, 

 on the other hand, are the product not only of uplift, but are largely 

 influenced by the sea, — its life, its sediments, and its surf erosion. 

 The latter are of little areal extent, especially on the north side, where 

 they form the merest fringe around the island. The uplands extend 

 close to the coast, where they are terminated by abruptly terraced 

 cliff's, or series of successively lower levels. 



The Inland Topograph}!. — This includes the whole surface of the 

 island except the narrow coastal plains and elevated reef, and is pecu- 

 liarly and strikingly diff"erent from any topography to which we are 

 accustomed in tlie United States. Under the influence of excessive 

 humidity, the solvent limestone material of which it is mostly composed 



