Todd-Carriker : Birds of Santa Marta Region, Colombia. 15 



Nevada proper on the western and southern sides. The outlying 

 foothills are thickly covered with shrubbery and low trees, largely of a 

 thorny character, and almost without exception deciduous, presenting 

 a parched and leafless aspect during the greater part of the year. But 

 with the first heavy rains they burst into leaf and flower with marvel- 

 ous rapidity. In fact this flora is more properly that of an arid than 

 a semi-arid region. It has been aptly called by Mr. Herbert H. Smith 

 the " dry forest," and is believed to represent an ancient and vanishing 

 flora. 



The foothills proper, on the other hand, are clothed with forests 

 composed of mingled deciduous and non-deciduous trees, together 

 with a great variety of shrubbery in the form of undergrowth. Few 

 thorn-bearing species are present. This the writer regards as the true 

 " dry forest," which is, properly speaking, characteristic only of the 

 foothills. This flora extends upwards to an extreme altitude of per- 

 haps 3,000 feet, but attains such an elevation only on narrow ex- 

 posed ridges and in but few places. It interdigitates with the humid 

 forest above, the latter always extending downward in the valleys, 

 gradually narrowing in width until at the lower edge of the foothills it 

 persists only along the immediate banks of the streams. This condi- 

 tion is found not only in the foothills of the Horqueta and San 

 Lorenzo, but also extends around on the west and south sides of the 

 Nevada, but not on the north coast for some distance, where the humid 

 forest extends practically unbroken down to the sea. 



Western Littoral and Foothills. — On the west side of the mountains, 

 from a point about midway between the town of Cienaga and Rio 

 Frio southward, the littoral is clothed with heavy, humid, tropical 

 forest, which in turn is separated from the humid forest of the upper 

 Tropical Zone by the dry forest of the intervening foothills. This 

 littoral forest is a continuation of that of the Magdalena basin, and 

 does not extend around to the south side of the Sierra Nevada beyond 

 Valencia, the valley of the Rio Cesar above that point being largely 

 occupied by open savannas, interspersed with clumps of more or less 

 " dry forest," and with the usual fringe of humid forest along the 

 banks of the streams, its width varying with the nature of the con- 

 tiguous terrain. If this is low and flat, then the- fringe of forest will 

 be wide; if shelving or sloping, it will be narrow. However, the "dry 

 forest " of the western foothills is more luxuriant than that of the 

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