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 tlie background against which the little harbors are cut out as far 

 west as Xiievitas. 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 Matauzas is also the result of the 

 wearing away of the limestone covering down to a floor of tuff's 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 Matauzas 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 Vunque, 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 



