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brown bv a thick vegetation of Chlorophyceae or Myxophyceae. 
Walls, rocks, stones, the bark of trees, old woodworks, etc., 
were nearly always wholly covered by algae; even an old iron 
can, which had been thrown into the river, had a bright green 
covering of a species of Chlorella. 
n a little waterfall in a brook, which empties into Maricao 
River, a little south of the town, there were found not only 
Hildenbrandtia, but also a species of Chantransia. In all there 
have now been found four fresh-water Florideae in Porto Rico. 
A rather rich vegetation of Chlorophyceae was found in some 
coast. Among the genera growing there, may be mentioned 
Spirogyra, Pithophora » Gonatonem ma, Rhizoclonium, Oedogonium, 
Nitella nedes: phe 
genus was otherwise not common in ne 
attention to on this journey, as its components belong rather 
to the salt-water algae. 
The twenty-sixth of February, I went to Arecibo and collected 
aerophilous algae on the walls in the town itself. The following 
Utuado. Tr ig 
limestone cliffs had considerable resemblance to the vegetation 
