Postelstia 
iat 
—~T 
At the higher elevations along the base of 
rocky ledges and in large crevices where there is 
enough soil to yield a foothold, the plants oc- 
curing most frequently are: 
Poly podium jalcatum Achlys tripiylla 
Asplenium trichoimanes Ttarella trijoliata 
Berberis nervosa Trientalis latijolia 
Mosses and lichens occur in considerable 
quantities upon the rocky ledges and shelves. 
San Juan Valley. The vegetation of the two 
valleys differs only in smaller details. This finds 
its explanation in the slope and trend of the 
palleveand im the nature of the sol.- The fall 
of the river in the same distance is not as great 
as that of the Gordon and one finds often along 
the banks small grassy meadows and forest open- 
ings, especially in the lower portions where there 
is considerable alluvial deposit. Farther up the 
valley are frequent evidences of moraines and 
although the surface soil is made up of decaying 
vegetation as everywhere else in the region, the 
subsoil is a moraine deposit and dissimilar con- 
ditions are therefore experienced. 
The direction of the harbor and the valley 
