6'3^ 



o 



PEEFACE. 



A PREFACE is indispensable in tliis instance, simply because I have no other 

 opportunity of properly acknowledging the assistance I have received in preparing 

 this work. I am particularlj^ indebted to Mr. J. A. Allen, of Cambridge, Mass., 

 who has diligently revised nearly all the proofsbeets, and whose critical suggestions 

 have proved invaluable. Mr. Robert Ridgway, of Illinois, has given me the 

 benefit of his still unpublished studies of the Raptoi-es and some other groups, 

 besides rendering, as Mr. Allen also has, various essential services. 



Prof. Baird kindly offered me the use of all the illustrations of his late 

 Review, while Prof. Agassiz generously placed at my disposal the plates 

 accompanying Mr. Allen's Memoir on the Birds of Florida. Several of the 

 woodcuts have been taken from Prof. Tenney's Manual of Zoology, with the 

 author's permission ; and a few others have been contributed by Messrs. Lee 

 and Shepakd. With a few exceptions, the rest of the illustrations have been 

 drawn from nature by the author, and engraved by Mr. C. A. Walker. 



I have spoken elsewhere of Prof. Marsh's almost indispensable cooperation 

 in one part of the work. 



While material for the greater part of the descriptions has been furnished by 

 the author's private cabinet, the Synopsis could hardly have been prepared without 

 that free access to the collection of the Smithsonian Institution, of which I 

 have been permitted to avail myself. 



The only word of explanation that seems to be required is with regard to the 

 large number of genera I have admitted. I have been led into this — unnecessariljr, 

 perhaps, and certainly against my judgment — partly by my desire to disturb a 

 current nomenclature as little as possible, and partly because it is still uncertain 

 what value should be attached to a generic name. Among wading and swimming 

 birds — the groups of which are, on the whole, more precisely limited than those of 

 Insessores — I have, however, indicated what I consider to be a reasonable reduc- 

 tion ; and on another occasion I should probably extend a like practice, if not one 

 even more " conservative," to the remaining groups. I will only add, that I 

 consider that several of the admitted families of Oscines will require to be merged 

 in one. These are the Tunlidce, SaxicoUdce and Sylviidce, if not also the Troglo- 

 dytidcB and MotacilUdce; while the same may prove true of the current Sylvieoline, 

 Tanagrine and Fringilline groups. 



E. C. 



Washington, D. C, September 9th, 1872. 



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