2o8 



THE FORESTER. 



September, 



later, the lower stretches of these nor- 

 thern streams present considerable areas 

 of bottom land, extending for some dis- 

 tances within the margin of the mountain 

 area, rarely broadening out into local 

 circular mountain valleys. Their upper 

 portions are steep angular gorges, how- 

 ever, where habitations are confined to 

 the slopes and not the valleys. There 

 are other streams of the island which 

 also present small areas of bottom land 

 indenting the mountanous area for a 

 very short distance from their coastal 

 borders, notably the Portugues, near 

 Ponce on the south, and the Anasco on 

 the west. 



The most unobservant traveler re- 

 marks the radical natural differences 

 which take place upon passing from the 

 mountains into the lower lying coastal 

 plains and foothills, especially upon the 

 south side. The coast-border topog 

 raphy comprises a narrow belt of low 

 hills and plains encircling the main 

 or mountainous mass of the island, and 

 broken in continuity upon the northeast, 

 southeast and west by spurs of the cen- 

 tral mountains which run across it into 

 the sea. This border region of itself is an 

 exceedingly diversified area, presenting 

 two conspicuous major types of relief, 

 coast hills and playa plains, and gener- 

 ally a third type, which may be called 

 parting valleys. 



On the north the coast hills stand as 

 steeply sloping solitary mounds or 

 domes, rising singly or in chains above 

 wider extents of plain lying between 

 them and the mountain front. The cit- 

 adels of San Juan are built upon a hill 

 of this character; others rise to the east 

 and west of the city as far as Rio Grande 

 and toward Arecibo. 



Along the shore from the southwest 

 cape of Porto Rico to within three or 

 four miles of Ponce, except where occa- 

 sionally broken by playas, coast hills are 

 finely developed. These hills, like those 

 of the north coast, are the remants of 

 what was once a steeply slanting bench 

 plain. The slant is from the central 

 mountains toward the sea, where the 

 hills are in some places terminated by a 



steep scarp or sea bluff ioo feet in 

 height. The interior side scarp of these 

 hills is bordered by a valley occupied 

 by the lake of Guanica, separated by 

 still another row of hills called the 

 cerros from the central mountains. 



On the southwest end of the island 

 there are two parallel rows of hills sepa- 

 rated from each other and the interior 

 mountains by long and fertile valleys. 

 The interior chain of hills, which ex- 

 tends from north of Cabo Rojo to within 

 three miles of Yauco, passing west of 

 San German, is of a peculiar type not 

 seen elsewhere on the island. It is a 

 single chain of highly rounded wooded 

 hills of the type called "knobs" in this 

 country, and "cerros" by the Spaniards. 

 They owe their configuration to a thick 

 cap stratum of hard mountain limestone, 

 the lower portion being composed of 

 the softer decomposing rock. Where 

 the cap has been removed erosion has 

 widened the valleys into great elongated 

 plains or vegas. 



For want of a better, the term "playa 

 plains " is used for the wide alluvial 

 plains found at more or less frequent in- 

 tervals along the entire coast between 

 the hills which limit them. The word 

 "playa" means literally "shore" or 

 "strand." Many 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, which is located at the immediate 

 seashore, and which is usually designated 

 "playa," in order to distinguish it from 

 the city proper. These playa plains are 

 usually fan- shaped in area, with their 

 broader base next to the sea, where they 

 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 with constantly decreasing width 

 backward up the stream valleys toward 

 the central mountains. Ponce is situated 

 upon a typical playa plain, which extends 

 a short distance back of the city up the 

 valley of the Rio Portugues. To the 

 west of Ponce the playa plains are quite 

 exceptional. 



