MUSEUM OF COMPARATIVE ZOOLOGY. 269 



twenty feet high (one hundred and seventy feet above the sea) worn out 

 of the lower part of the old white limestone. Its sides are vertical in 

 most places; and inaccessible. This clitf is in turn surmounted by another 

 bench (Xo. 2), which was likewise formerly an old beach level, from 

 which any renmant of the deposit that may have once existed has been 

 eroded. It is covered by a dense growth of vegetation. The river 

 canon which cuts across these cliffs and benches shows that they are 

 not elevated built-up coral reefs, but are clearly cut sea terraces in the 

 old limestone. The second bench is about a hundred feet in width, and 

 abuts against a second vertical cliff, the summit of which is nearly as 

 high as that of the first one, or about three hundi'ed and fifty feet above 

 the sea. The level bench (No. 3) mounting this cliff is similar in appear- 

 ance to No. 2. 



This last bench in turn abuts against a third and uppermost escarp- 

 ment of the highland, which terminates at a height of from five hundred 

 to six hundred feet in the irregular upland plain forming the fourth 

 level above the sea. 



The Cuchilla Level. — This fourth level is the genei'al upland plain as 

 it appears from the sea, and represents the old land from which was 

 carved the group of cliffs above described. This highest escarpment 

 forms a comparatively unbroken plateau at the eastern end of the 

 island, overlooking the sea, but westward the increasing drainage cuts 

 it more and more into numerous serrated hills known as the Cuchillas, 

 or " Knives," whose summits have a general culmination of from five 

 hundred to six hundred feet, and are clearly remnants of the Yumuri 

 Plateau. These Cuchillas form a very conspicuous coast feature from 

 Nuevitas to the east end of the island. 



The Tunqve, or Higher Level. — A single glance, at the peculiar iso- 

 lated mountain known as the Yunque, or Anvil, situated six miles west 

 of Baracoa, is sufficient to show that its sub-level summit is the remnant 

 of an ancient higher level than that represented by the Cuchillas.^ This 

 is a magnificent butte, whose summit is put upon the pilot chart at 

 eighteen hundred feet, and so estimated by Crosby.* The summit is an 

 ovoid mesa, which is apparently level, but which really shows deeply 

 carved drainage ways and ancient topography indicating long exposure. 

 The upper portion is composed of a mass of the older tertiary rocks one 

 thousand feet in thickness, whose perimeter is an almost inaccessible 

 cliff. This rests upon a base composed of the metamorphic rocks of the 



1 A. Agassiz, Bull, Mus. Comp. Zool., Vol. XXVI. No. 1, Plate XLI. 



2 Op. at. 



