INTRODUCTION. 
One of the greatest of Mr. Seebohm's discoveries in ornithology was the application of the 
character of the plumage of the young birds for the differentiation of the Thrushes (Turdidae) from 
the Warblers (Sylviide). The former have but one moult in the year, while the latter have 
two—one in autumn and another in spring. The young Thrushes have a spotted plumage, 
while the young Warblers have a plain dress, not very different from the plumage of their 
parents. 
Among Ше Turdide, therefore, should have been placed, not only the true Thrushes, but 
also all Saxicole (Wheatears), Cossyphe (Robin-Thrushes), Erithaci (Robins, Nightingales, 
Bluethroats, &c.), Pratincole (Stonechats, &c.) and many other birds with spotted young and 
a single (autumnal) moult. Of this vast group but a small portion falls under the heading 
of the present Monograph, and the title of the work is therefore somewhat of a misnomer, 
as the book deals with the true Thrushes only; but of these the account will, it is hoped, be 
found to be tolerably complete. The Monograph follows the lines of Mr. Seebohm's volume 
of the “Catalogue of Birds'—an arrangement which has been somewhat modified in recent 
years by the researches of American naturalists, Dr. Stejneger, Mr. Oberholser, and others, and 
by Mr. Eugene W. Oates in England. 
In repeating my sincere apologies to the Subscribers for the unavoidable delay which has 
taken place in the completion of the work, I cannot omit to thank the Publishers for the 
generous manner in which fhey have provided new coloured Plates for such species as were 
discovered during the earlier progress of the work. Such new species as it was not possible to 
illustrate will be found duly recorded in the “Table of Contents” and in the “ Appendix” to the 
second volume. 
R. BOWDLER SHARPE. 
Chiswick, December 1902. 
