History of the Island of Cuba. 205 



sists of the older metamorpliic rocks. The Sierra San Juan 

 and the high ridges of the central portion of the island are 

 remnants of the same old. level, and differ from the more iso- 

 lated summits in having been less eroded. These have no 

 regularity of arrangement or trend, but are found in irregular 

 patches throughout the island. Their slopes are entirely the 

 product of solution and erosion. 



The Spanish language to which our geographic nomencla- 

 ture is already so much indebted, has provided an appropriate 

 name for another class of mountains. These are the Cuchillas, 

 or "knives" so called because of the numerous sharp salients 

 marking their slopes, and caused by the deep incision of an 

 old plain or general level of which they are the fast fading 

 remnant. These are the sharply serrated hills, forming the 

 sharp background to the coasts, especially at the east end of 

 the island. Their summits never exceed 600 feet in altitude, 

 and are clearly the remnants of a general plain of that alti- 

 tude. The Cuchillas are generally composed of the old lime- 

 stone which dips at many angles and degrees, but sometimes 

 they consist of a complexity of limestones, yellow beds, 

 Radiolarian beds, and the old metamorphic floor. At Yumuri 

 and around Cape Mayci, they consist of a more massive and 

 unbroken wall of the old limestone ; but as we go westward 

 they become more eroded, as illustrated by the high line of 

 hills along the coast and the background against which the little 

 harbors are cut out as far west as ]STuevitas. Still westward the 

 contour recedes slightly inland. On the south of Santiago 

 coast the same level of the Cuchillas summits are 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 adja- 

 cent to Villa Clara and Puerto Principe which are clearly 

 structural remnants of the older metamorphic floor from which 

 the folded limestones have been eroded, the latter often being 

 preserved on top of the higher elevations or sharply inclined 

 around their edges. The series of sharply rounded hills be- 

 tween Havana and Matanzas is also the result of the wearing 

 away of the limestone-covering down to a floor of tuffs and 

 serpentines, which, owing to its softer nature is more deeply 

 and sharply sculptured than the limestone regions proper. 



Although the close of the Tertiary was marked by much 

 folding, recognizable mountains conforming to the structural 

 folds were not seen by me. 



Terraces and Benches. — The most striking feature in the 

 topography of Cuba is the well defined terraces and benches 

 which mark its coasts in many places. These are often so dis- 

 tinct, especially at the east end of the island that their con- 



