Todd-Carriker : Birds of Santa Marta Region, Colombia. 579 



which was probably some form of F. rufipectus, since this is the only 

 species of the genus to be expected in the Subtropical Zone. The 

 crest is about 5,000 feet here, but the trail crosses through a small gap, 

 some 500 feet lower down. Just after passing the gap, but still in the 

 heavy forest belt, I took the specimen of Dysithaumus olivaceus. 



" Within a quarter of a mile below the crest of the range, on the 

 south side, there is a rapid and striking change in the vegetation, mark- 

 ing our re-entrance into the Tropical Zone. The forest gives way to 

 a straggling growth of low, open woodland, choked with undergrowth. 

 Deciduous trees soon appear, and when an elevation of about 3,000 

 feet is reached in the descent acacias and cacti put in an appearance, 

 gradually replacing all other forms, until when the foothills along the 

 Rio Rancheria are reached the flora (and fauna) is typically that of the 

 Arid Tropical. The trail crosses the river just at the point where it 

 breaks out of the hills, and from there downward to Fonseca its flood- 

 plain is very broad and heavily wooded, although the trees are very . 

 largely of the ' dry forest ' types. Birds were abundant around Fon- 

 seca, especially in the forest of the flood-plain, where several new 

 forms were first observed, among them Heleodytes nuchalis. With the 

 exception of this one species, however, the birds found here belonged 

 to the Rio Hacha-Dibulla fauna, those inhabiting the flood-plain 

 woodland more nearly corresponding to those recorded from Dibulla, 

 while those of the outlying scrub were the same as were noted at Rio 

 Hacha. 



" The road from Fonseca to San Juan de Cesar closely skirts the 

 lower edge of the foothills, which rise abruptly from a level plain. 

 The vegetation of this plain is precisely that of the region about Rio 

 Hacha, and the avifauna is practically the same. The slopes and 

 ridges of the foothills are here mostly bare clay and rock or covered 

 with coarse grasses, but there is a light growth of woodland present 

 in the narrow valleys and ravines. About midway between the two 

 towns just mentioned the divide between the Rio Rancheria and Rio 

 Cesar is crossed, but it is almost imperceptible. San Juan de Cesar is 

 also near the foothills, and the river here is small. The surrounding 

 country, except for the narrow flood-plain, is covered with the same 

 cacti and dry, acacia-like vegetation, with a few scattered tracts of 

 open land, superficially resembling savannas. 



