INTRODUCTION. 
In*the first volume will be found an account of the Lemuvordea, 
and the Anxthropoidea as far as the group of the Macaques of 
the family Cercopithecide. The second volume continues with 
the latter genus, and contains the rest of the Monkeys, and 
the Apes, as well as a summary of the geographical distribution 
of the species of the Order Primates. 
I have not attempted to write a complete synonymy of the 
species of Monkeys. ‘The literature is scattered over many, 
often obscure, periodicals, and without seeing the actual speci- 
mens described by some of the older writers, it would be easy 
to introduce a great deal of confusion into the synonymy. I 
have, therefore, only attempted to give the principal references. 
I must express my obligation to Dr. Giinther, F.R.S., the 
Keeper of the Zoological Department in the British Museum, 
for the facilities of study afforded to me in that institution. 
To Mr. Oldfield Thomas I am likewise greatly indebted for 
much assistance, and for many a kindly hint. 
Dr. Forsyth Major, who is well-known as one of the fore- 
most authorities on the Lemurs, not only gave me valuable 
information as to the species and literature of the Zemuvroidea, 
but was even so good as to furnish me with the descriptions 
of several new species. 
