PREFACE. ix 
The part of the Amazons region where I resided longest 
being unexplored country to the Naturalist, no less than 8000 
of the species here enumerated were mew to science, and these 
are now occupying the busy pens of a number of learned men 
in different parts of Europe to describe them. The few new 
mammals have been named by Dr. Gray; the birds by 
Dr. Sclater ; the zoophytes by Dr. Bowerbank ; and the more 
numerous novelties in reptiles and fishes are now in course of 
publication by Dr. Giinther. 
A word will perhaps be here in place with reference to what 
has become of these large collections. It will be an occasion 
for regret to many Naturalists to learn that a complete set of 
the species has nowhere been preserved, seeing that this would 
have formed a fair illustration of the Fauna of a region not 
likely to be explored again for the same purpose in our time. - 
The limited means of a private traveller do not admit of his 
keeping, for a purely scientific end, a large collection. A 
considerable number, from many of the consignments which 
arrived in London from time to time, were chosen for the 
British Museum, so that the largest set next to my own is 
contained in our National Collection ; but this probably com- 
prises less than half the total number of species obtained. My 
very complete private collection of insects of nearly all the 
orders, which was especially valuable as containing the various 
connecting varieties, ticketed with their exact localities for the 
purpose of illustrating the formation of races, does not now 
exist in its entirety, a few large groups having passed into 
private hands in different parts of Europe. 
With regard to the illustrations with which my book is 
adorned, it requires to be mentioned that the Natural History 
subjects have been drawn chiefly from specimens obtained by 
