PREFACE. 
XXI 
and quoted only the works which he has consulted ; except in 
a few instances, where it appeared requisite to refer to certain 
authors whose works he has not seen, but in such circumstances 
the reference is enclosed by ( ), and precedes the title of the 
work whence it was extracted, so as to leave no risk of mistake. 
While the author, as a compiler, has cause to lament the in- 
abilities under which he has laboured, he trusts to be forgiven, 
if he ventures, as a compensation for acknowledged defects, to 
prefer some claims on the confidence of the reader. He has re- 
ceived many valuable contributions from kind friends, whose fa- 
vours he trusts he has not been reluctant to acknowledge. He 
has long been a practical observer of British Animals, or what 
a friend of the Honourable Daines Barrington used to term 
an Out-door Naturalist. This circumstance has enabled him to 
correct the specific characters of several animals, and to point 
out with greater accuracy their habits and distribution, to sup- 
press several spurious species, and to give to the synonimes, in 
many cases, a greater degree of precision. He trusts the addi^ 
tlons to the British Fauna which he has here contributed will 
not at the same time be overlooked. 
In the description of species, the author has seldom indulged 
in physiological details or delineations of instinct. He refers 
to his Philosophy of Zoology, to which the present work is des- 
tined to serve as an adjunct, for ample illustrations on these 
subjects. To the same quarter he must direct the reader who 
wishes to comprehend more fuUy the principles of the Dichoto- 
mous Method^ which he has followed throughout. He is aware 
that the Quinary and Circular Disposition of Animals proposed 
by Mr Macleay, has several followers. This novel method, 
however, seems to have originated in metaphysical prejudices, 
and by overlooking the fact, that, in the various organs and 
their numerous modifications, belonging to each species, there 
are characters which enable the physiologist to trace resem- 
blances in structure and function with the organs of many other 
species : So that the same animal may occupy a place in many 
different physiological groups, and yield the most convenient 
facilities to those who intend to arrange the species according 
to any preconceived plan. 
