vi PREFACE 
replace some which were already occupied ; these have been pro- 
posed by Mr. Lydekker, and should be quoted as‘his. 
The work is based largely upon the article “Mammalia,” to- 
gether with forty shorter articles, written by the senior of the two 
authors for the ninth edition of the Encyclopedia Britannica. The 
account of the orders Rodentia, Insectivora, and Chiroptera con- 
tributed to the article “Mammalia” by Dr. G. E. Dobson, F.R.S., 
as well as the articles “Mole,” “Shrew,” and “ Vampyre,” by the 
same writer, the articles “ Marmot,” “Mouse,” “Opossum,” “ Phal- 
anger,” “Rat,” “Squirrel,” “Stoat,” “Vole,” and others, by Mr. 
Oldfield Thomas, and likewise the article “Ape,” by Dr. St. G. 
Mivart, F.R.S., have also been made use of to a greater or less 
extent. The best thanks of the authors are due to these three 
gentlemen for freely permitting the incorporation of their own 
work in the present volume. 
Mr. Lydekker undertook the task of arranging the various 
articles in their proper sequence, selecting from these such portions 
as seemed suitable, fillmg up the gaps, and adding new matter 
where necessary ; a large amount of this new matter treating of the 
extinct forms, and also of the group Artiodactyla. 
The subsequent revision, both before being sent to the printers, 
and also when passing through the press, has been made by both 
authors, who are thus jointly responsible for the whole work. 
The illustrations are to a great extent those prepared for the 
various articles in the Encyclopaedia, but many have been added 
—some drawn expressly for the work, and some borrowed from 
other publications. For most of the latter the authors take this 
opportunity of expressing their thanks to the Publication Com- 
