MUSEUM OF COMPARATIVE ZOOLOGY. 263 
and unbroken wall of the old limestone, but as we go westward they 
become more dissected, as in the line of high hills along the coast, and 
in the background against which the little harbors are cut out as far 
west as Nuevitas. Still farther westward the contour recedes slightly 
inland. On the south or Santiago coast, the same level of the cuchillas 
summits is preserved in diorite and syenite. 
In addition to the limestone mountains of erosion described, there are 
many low hills in the central part of the island adjacent to Villa Clara 
(Plate IV.) and Puerto Principe which are clearly structural remnants 
of the older metamorphic floor, from which the folded limestones have 
been eroded, the latter being often preserved on top of the higher ele- 
vations, or sharply inclined around their edges. The series of sharply 
rounded hills between Havana and Matanzas is also the result of the 
wearing away of the limestone covering down to a floor of tuffs and ser- 
pentines, which, owing to its softer nature, is more deeply and sharply 
sculptured than the limestone regions proper. 
Concerning the geology of the Sierra Maestra of Santiago, Kimball 
says that the old limestones preserved on their slopes show that at 
least twenty-three hundred feet of their elevation are Post-Tertiary, and 
there is no recorded evidence of any Post-Tertiary eruptives or flows. 
I incline to believe that these ranges belong in the same class with those 
of the Villa Clara type. Although the close of the Tertiary was marked 
by much folding, recognizable mountains simulating Post-Tertiary struc- 
tural folds, or evidences of Post-Tertiary extensive volcanic action, are 
certainly rare, if they exist at all. The present irregularities are all 
the result of erosion. I made every possible reconnoissance over the 
island to study the upland topography, and I think my conclusions are 
founded on abundant evidence, proving beyond doubt that the higher 
limestone elevations are solely the remnant of the former area of the 
older limestone mass. For instance, the sharp lines of limestone sum- 
mits on the high divide of the island between Havana and Batabano are 
clearly the old scarps of the Armendaris drainage cut out of a former 
plateau. The mountains on the road from Havana to Villa Clara and 
back of Matanzas are either of similar character, or are the perimeters 
(knobs) of vast basins, like the sink-holes of other limestone regions, 
only much larger, owing to the more solvent nature of the substructure. 
The isolated mountains of high elevation along the north coast, like 
the Pan de Matanzas and the Yunque, are fragments of the older areal 
summits, which have been separated by circumscribing erosion from 
the main body of the upland, and stand as solitary remnants of the 
