YORKSHIRE—VERTEBRATE FAUNA. xlv 
The authors offer no apology for undertaking the task, for 
none is necessary. A Yorkshire list had never been published, 
and it was within their power to supply the desideratum, partly 
because for some years they had systematically investigated the 
literature of the subject, and partly on account of the advantage 
they possessed in being in communication with the leading 
naturalists of the county. On another page they have endeavoured 
to express—eyven though inadequately—their sense of obligation 
to those who have contributed towards the materials upon which 
this work is founded. That such a work as the present was 
required is amply proved by the large amount of interesting 
matter now published for the first time. The voluminous nature 
of the evidence upon which the work is founded is shown by the 
list of contributors given at the end ; and the separate authorship 
of each section of the list is sufficiently indicated by the flysheets 
inserted. 
It cannot of course be expected that error has been entirely 
avoided, especially in the case of a work which in the essential 
part of its design has no predecessor but Mr. J. E. Harting’s 
excellent and indispensable ‘Handbook of British Birds’; but 
—-so far as an exhaustive examination of the literature of the 
subject, together with the unanimous and generous assistance 
received from the naturalists of the county, and the exercise of 
scrupulous care in judging evidence, are concerned—it is believed 
that the chances of error have been reduced to a minimum. 
