MUSEUM OF COMPARATIVE ZOOLOGY. 267 
now seen at Baracoa, where the surf line, which enters the narrow bay 
with gathered force, breaks against the unconsolidated miocene yellow 
deposit constituting the sides of the harbor back of the elevated reef, 
and huge blocks of the latter constantly topple over into the bay. 
There is general remark throughout Cuba that the harbors are becom- 
ing shallower. Captain McIntyre, a trustworthy mariner, who has been 
trading at Baracoa for over forty years, assured me that within his 
memory the anchorage area has steadily decreased, and that ships which 
formerly discharged their cargoes at a pier, are now dependent upon 
lighters. While it is very probable that the silt from the rivers is a 
partial cause of this, it may be probable that steady elevation now going 
on, as it has certainly gone on in very recent time, may be productive of 
the shallowing. 
The ovoid harbors thus developed from the simple type of river 
emptying directly into the sea and undermining the contiguous reefs 
attain a third stage (Plate II. Figs. 7 and 4) in which the regular margins 
become denticulated and irregularly indented by erosion, as seen in the 
harbors of Havana and Escondido. In the harbor of Havana the ex- 
cessive irregularity of the interior margin is increased by the fact that 
the limestone background has been cut through down to the tuffs, 
serpentines, and clays underlying it, which degrade into more irregular 
topography than that of the limestones. 
Terraces and Benches. 
The most striking feature in the topography of Cuba consists of the 
well defined terraces and benches which mark its coasts in many places. 
These are often so distinct, especially at the east end of the island, that 
their continuity is traceable for many miles, as they rise abruptly from 
the water’s level, one above the other, in a series of cliffs. On the west 
end of the island they are not so distinctly visible from any single point 
of view, for the flat benches are much wider, but they are nevertheless 
traceable. In other places denudation has destroyed them. 
Besides these benches and terraces, whose integrity is distinctly pre- 
served, remnants of older and more denuded levels can be traced, and 
for convenience they may be classified as follows : — 
4. The Soboruco, or elevated reef level. 
3. Elevated beach and cliff lines and 1. Later (Lower) levels. 
the Havana base levels. 
2. The Cuchilla level. 
1. The Yunque level. t 2 Older, (Hip hen evs. 
