MUSEUM OF COMPARATIVE ZOOLOGY. 271 



Carmelo are built. It terminates inland in a limestone escarpment 

 of erosion, which has worn down to the underlying floor of igneous 

 tuffs. 



There can be no doubt that this peninsula was once an eastward con- 

 tinuation across Havana Bay of the plateau west of the Eio Armendaris 

 and the Moro Plateau, and that it has been disconnected from them by 

 the streams which flow in the intervening valleys. The plateau in 

 which Moro Castle is situated is similar in surface and structural features 

 to that of the Castillo Principe, and liliewise terminated inland in the 

 hilly region north of Picgla by an escarpment of stratification which 

 destroys the possibility of tracing its former extent inland. In area it 

 represents an elongated east and west narrow platform forming a vertical 

 coast line as far as Guanos Point, and extending toward Matanzas, where 

 I think its level is represented by some of the terraces in that vicinity, 

 and projecting, in places, as at Moro Point, fully to the ocean's edge. 

 This general level of the Moro Plateau is not an elevated coral reef, but 

 is an ancient level of erosion representing a period in the history of the 

 island when the area it now occupies was approximately near sea level, 

 and which has been subsequently elevated. Its surface in no manner 

 represents a deposition plain or the surface of an old reef growth, but is 

 produced solely by base-levelling erosion, and this in spite of the irregu- 

 lar sinuosities seen in its substructure, the old tertiary limestone. 



The Caniera Elevation. — Around the base of the Castillo Principe 

 Plateau may be traced the remnants of another level, approximately 

 twenty-five meters (eighty-five feet) in height, which, for convenience, 

 I will term the Cantera level. This, too, represents another and later 

 epoch of levelling, and has likewise been greatly destroyed by later 

 erosion. Below it, and adjacent to the sea, is the soboruco, or elevated 

 reef level. 



Older Levels. — Back of Havana there is a line of still liigher, greatly 

 eroded hills, which overlook these levels, and have an altitude of about 

 five hundred feet, merging southward into a plateau constituting the 

 divide between the north and south shores of the island. This lime- 

 stone plateau gently slopes away to the south coast, and undoubtedl}' 

 once covered the hilly area back of Havana. The highest point on the 

 railway, which goes through a saddle, is 101 meters (332 feet), the 

 country rising to about two hundred feet above this. 



The Matanzas Levels. — Matanzas Bay diff'ers from the general type of 

 the sac-like harbors of the north coast only in that it is rhoraboidal 

 in form, and seems more deeply cut into the high background which sur- 



