INTRODUCTION. ix 
Newton’s admirable edition of Yarrell’s ‘ British Birds’ been 
complete—or nearly so—it would undoubtedly have been 
adopted as a guide by virtue of the position which it admittedly 
holds as the standard work on British Ornithology. In such an 
event practical convenience would—and rightly so—have over- 
ruled all other considerations. But this unfortunately not being 
the case, it became necessary to consider the present state of 
ornithological opinion as to the classification of Birds. This has 
been admirably summarised in the Ibis for 1880, by Dr. P. L. 
Sclater, in a paper entitled ‘ Remarks on the present state of the 
Systema Avium.’ The arrangement therein promulgated—or 
some modification of it—seems likely to meet with acceptance 
more or less general at the hands of ornithologists, and has 
already been adopted by Mr. H. E. Dresser in his recently-com- 
pleted great work on the Birds of Europe. The arrangement and 
nomenclature of Mr. Dresser’s work have therefore been followed. 
It is not within the province of a work of this character to 
decide whether certain birds ought or ought not to be included 
in the list, and consequently all admitted as British by Mr. 
Dresser, or included by Mr. Wharton in his excellent little cata- 
logue, have, with trifling exceptions, been here included. There 
are, however, certain species which have been reported as occur- 
ring in Yorkshire on evidence which is regarded by authors as 
more or less insufficient for their admission into the British fauna. 
These are inserted in their zoological position, but—in order 
that it may be quite clear that their claims are not fully accepted 
—no numbers are prefixed. Nor are they prefixed to Cygnus olor 
and Alca impennis—the first a domesticated bird and the second 
admittedly extinct. 
Reptiles and Amphibians.— The lists of reptiles and 
amphibians are founded upon Bell’s British Reptiles and the 
writings of Dr. Giinther and Mr. St. George Mivart. An amphi- 
bian, however, which has been described in the works of Bell and 
Cooke—Ommatotriton vittatus or Gray's Banded Newt, a Syrian 
