PREFACE . 
viii 
in due zoological order follow the Moles and Shrews, 
the Foxes, the Weasels, the Rodents, and the Edentates. 
The White Bear alone is removed from its legitimate 
place, on account of its singular habitation in the snow. 
The Burrowing Birds come next in order, those which 
burrow in the earth taking precedence of those which 
make holes in wood. Burrowing Reptiles follow next 
in order; and then come the Burrowing Invertebrates, 
headed by the Crustacea. The same system is followed 
throughout, so as to give the reader a clear and definite 
idea of the subject. 
On perusing the work, the attentive reader will pro- 
bably discover that various animals are placed in one 
class when they might very well be in another. The 
reason is, that many creatures, such as the wasp, the 
ant, the squirrel, &c., might with equal propriety find a 
place in several of these classes, and I have therefore 
placed them in that class of which some peculiarity in 
nest-making renders them fit illustrators. 
I must now return my thanks to the many friends 
who have assisted me in the work, by the loan or gift of 
specimens, or by affording valuable information. Among 
them I must especially mention J. Gould, Esq., who 
kindly took an interest in the ornithological , portion of 
the work; F. SMITH, Esq., of the British Museum ; and 
the late CHARLES WATERTON, Esq., who permitted me 
the use of his museum, and gave me much interesting 
and useful information. 
