PORTO RICO 



103 



IBAN'A GRANDE 



hills and are found at more or less frequent intervals along 

 the entire coast, the borders of which delimit them. I have 

 used the word playa plains for this feature merely as a conven- 

 ient designation. The word " playa " means literally the shore 

 or strand. Many of the cities of Porto Rico are situated upon 

 the interior border of such plains, where they meet the foot- 

 hills several miles from the port of entry at the immediate sea- 

 shore, which is usually designated "playa," in order to dis- 

 tinguish it from the city proper. These plains are fan-shaped 

 in area, with their broader base next to the sea, where the}' are 

 often many miles in width, and stand only a few feet above the 

 ocean. They are bordered by escarpments composed of the 

 sharp rise of the coast hills, and extend backward up the stream 

 valleys toward the central mountains with gently rising altitude 

 until the} r pass into a mountain gorge or quebrada. These plains 

 are composed of rich alluvial soil, principally reddish sandy 

 loams, and constitute the sugar lands of the island. These are 

 now what were formerly old alluvial river estuaries, which in 

 late geologic time constituted bays indenting the land, and which 

 have been reclaimed by the general elevation of the island. 



These plains are in many cases so extensive that they now far 

 exceed the area of the limestone bench out of which they were 

 originally carved, and in places the surviving hills of the bench 

 are almost entirely removed. 



On the north coast the coast hills stand as steeply sloping soli- 

 tary mounds or domes, rising singly or in chains above wider ex- 

 tents of plain lying between them and the mountain front. The 



