56 
transition from dry to wet vegetation may also be observed 
In th 
2700 feet, some of the elegant forest plants were foun 
mosses than any aiher visited yeas the trip. 
A study was made of one of the aerate of the Sierra de 
endem ccurs at the summit ere the dom 
the achiotillo (Alchornea latifolia) and the lechesillo (Sapium 
Laurocerasus), both of the spurge family, with a few specimens 
of ntain palm. 
n March 18th we moved our base of operations from Coamo 
a t others 
of the limestone hills; an ae fro oe erosion of this oe 
the sand seems to have been derived. Excav: ati ns fo 
areas extend more or less continuously from near Loi he 
east to beyond Manati on the west, a distance = at least 30 
miles, and in places they are half a mile or more wide. 
his 
sand supports a native vegetation of plants eee physiology 
