5 
stretching along the south and east coasts, and it encroaches 
into the savannah at many points for some miles beyond its usual 
fase The savannah or ‘“Ilanos ’ is a great plain covered with 
ough wiry grass, with a considerable sprinkling of small 
ae oft bush. All the country south of the before-mentioned 
range is slightly above sea level, the hills of two or three hundred 
feet that are often found being of no especial importance ecolog- 
ically. 
These three provinces of Samana, Seibo and Macoris contain 
scores of rivers, great and small. The most important one is the 
Yuna, a stream some 230 miles long, which flows from the Cibao 
to Samana Bay. This river and its affluents water a large 
hydrographic basin, but at its mouth it is nota large or deep 
stream. f the rivers that take their rise in the mountain chain 
and flow north or south, the most important are the Casui and 
Macoris, Soco, and Chavon, all flowing south and all sluggish, 
except during the freshets: These three rivers and their branches, 
together with a number of smaller streams, are the chief water 
courses in the region south of the mountain chain. Commercially, 
one of them at least is more important than the thrice greater 
Yuna, but all of them have small hydrographic basins, and are not 
so important, ecologically, as the Yuna with its many affluents 
and great sphere of influence. 
There is a great deal of variation in the amount, distribution 
and periodicity of the rains in Santo Domingo. Along the nort 
observations. Along the south coast heavy rains may be ex- 
pected in July, August, September and October, and sometimes 
also in June.* Scattered showers occur throwehout the year. 
* The weather and rainfall records of the south coast are based on figures kindly 
placed at my disposal by Mr. H. F. D. Burke, the Director-General of public 
works, Santo Domingo City ; a also those taken at the a ai sugar-estate, 
San Pedro de Macoris, secured through the courtesy of Mr. G. n. 
