MUSEUM OF COMPARATIVE ZOOLOGY. 259 
to the genesis of the island. Its shape and outline have been described 
by various writers, notably Humboldt, Sagra, and Réclus, 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 island, while the fins are represeuted by 
pendant coral reef archipelagos. The Santiago coast is excessively 
mountainous, and is supposed to be in some way genetically connected 
with the mountain systems of the other Antilles. Concerning the com- 
position, age, and topography of these ranges, we know little except 
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 portion of the island, and occupy a very narrow 
strip close to the ocean’s margin. Extending away to the north and 
west from this nucleal 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 the 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 remnants of a dissected elevated 
plateau, diversified by plains and irregular chains of hills, often nearer 
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 those of the coast. The former depend upon uplift and erosion, and 
are mostly the product of superficial agencies. The coastal features, 
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 
cliffs, or series of successively lower levels. 
The Inland Topography. — This includes the whole surface of the 
island except the narrow coastal plains and elevated reef, and is pecu- 
liarly and strikingly different from any topography to which we are 
accustomed in the United States. Under the influence of excessive 
humidity, the solvent limestone material of which it is mostly composed 
