PREFACE. vii 
standard ornithological works, especially D. Appleton & Co., Dana Estes 
& Co., Little Brown & Co., Houghton, Mifflin & Co., and a few others, 
credit being given for each illustration as used. Special mention should 
be made of Plate I (Frontispiece), the Topography of a Bird, from Ridg- 
way’s Nomenclature of Colors (1886), by special permission of the author, 
and of Plate 70, the Hermit Thrush, presented by the artist, Mr. W. F. 
Jackson, of Mayfield, Michigan. 
I am under special obligation to Dr. Robert Ridgway and Dr. C. W. 
Richmond of the U. 8. National Museum, and to Dr. C. Hart Merriam, 
Dr. A. K. Fisher, Dr. T. 8. Palmer, H. W. Henshaw, and other members 
of the Bureau of Biological Survey of the U. 8. Department of Agri- 
culture, for the examination of specimens, the verification of references, 
and many critical notes and suggestions. In addition, the Biological 
Survey kindly allowed the use of all its migration schedules from Mich- 
igan observers, together with the reports of lighthouse keepers at all Mich- 
igan lights. 
The artificial keys, already alluded to, are mainly original, at least 
in their present form, but in constructing them use has been made of 
similar keys in various publications, particularly Ridgway’s Manual, 
Coues’ Key, and Chapman’s Handbook. The technical descriptions also 
are original for the most part, having been written with specimens in 
hand, but of course after comparison with the best published descriptions 
available. In the case of a species not properly represented in our own 
collections the description given by Ridgway has usually been copied 
verbatim (between quotation marks), or, in a few instances the original 
describer has been quoted in the same way. The measurements given 
in the technical descriptions are usually from Ridgway’s Manual of North 
American Birds (1887), and the same is true for the measurements of 
eggs. Dr. Ridgway’s permission to do this is greatfully acknowledged. 
