PREFACE 
Tis Dictionary has taken me far longer to complete than, 
when I began it, I had any notion that it would. Yet I do not 
regret the delay, since it has enabled me, though very briefly, 
to shew (INTRODUCTION, page 108, note) that the latest investi- 
gation has proved the newly-announced group STEREORNITHES, 
which seemed at first so important, to have no more claim to 
recognition than had that known as ODONTORNITHES. 
The articles by Dr. Gapow have fully sustained the 
expectation of them expressed in my initial NoTr. Read with 
the aid of the cross-references they contain and the INDex that 
follows, they cannot fail to place the enquirer, be he beginner 
or advanced student, in a position he could not hope to occupy 
through the study of any other English book, and, what is 
better, a position whence he may extend his researches in many 
directions. 
It has been my object throughout to compress into the 
smallest compass the information intended to be conveyed. 
It would have been easier to double the bulk of the work, 
but the limits of a single volume are already strained, and to 
extend it to a second would in several ways destroy such 
usefulness as it may possess. Still I cannot but regret having 
to omit any special notice of several interesting subjects which 
bear more or less directly upon Ornithology. To name only a 
few of them—Insulation, Isomorphism, Reversion and _ the 
