2 INTRODUCTION. 
or I had doubts of the correct determination of such specimens 
as were in my possession. im sil such cases I have, when pos- 
sible, taken the descriptions from the ‘Senopsis Muscorum Fron- 
dosum, of Dr. Carl Müller, chiefly because bis characters, when 
he had himself seen the species, are good. and also because he has 
examined many of the species whieh arc not found in any British 
herbarium that I have exanuaed, and he has written them ah 
"non one uniform plan. 
T have adhered as nearly as possible, in the nomenclature, to 
the use of names which have the right of priority, so far as I 
have been able to ascertain it. 
A very large proportion of the plants colleeted by Mr. Spruce 
were gathered towards the frontiers of various countries (Brazil, 
Venezuela, New Granada, Ecuador, and Peru) ; and as the actual 
position of these frontiers is still in many cases a subject of 
dispute, he judged it best to ignore ali politieal divisions, and to 
group all the localities under the great natural regions marked 
out by the rivers and mountains, in the following manner— 
i, Fiumen Amazonum, 
2. Fiuvium Negro, 
3. Flumen Orinoco, 
4. Andes Quitenses sive ZEquatoriales, 
5. Andes Peruviane ; 
and the subjoined brief account of them will suffice to render it 
easy to find any of the specified localities on an ordinary map. 
1. The river Amazons. from its mouth to the roots of the Andes, 
with its tributaries the Tapajoz, the Trombetas (with its af- 
fluent the Avipecurt), the Huallaga, the Pastasa. 
2. The Kio Negro, from its confluence with the Amazons to 
its sources in Venezuela, including several of its afluents, among 
which are the Casequiari, branching from the Orinoco. The 
whole basin of the Rio Negro belongs, of course, to the Amazons 
valley, and the lower part of it, up to near the mouth of the Rio 
Blanco, or to where the granite begins, ought properly to be 
included iz the Amazons district; very few mosses, however, were 
gathered in that part, and nothing of special interest. 
3. The river Orinoco, from the cataracts of Maypures up- 
wards, including its tributary the Atabapo. 
4. The Quitenmu Andes, extendmg from Pasto on the north 
to the river Marañon for Amazons) on the south. The great 
forest of Canelos is ineluded in this district. Tt lies just south 
