VI PREFACE. 



institutions as have already been named in previous volumes; also 

 to Mr. C. H. Lankester, of CachI, Costa Rica, who kindly placed the 

 Tracheophones of his line collection of Costa Rican birds at the au- 

 thor's service. 



To Senor Don Jose C. Zeledon, of vSan Jose, Costa Rica, the author 

 is specially indebted for most generous help, at considerable expense 

 to himself, in making a very fine collection of the birds of that country, 

 which proved of incalculable value in the preparation of tliis work. 



Dr. C. W. Richmond, Assistant Curator, and Mr. J. II. Riley, Aid, 

 of the Division of Birds, U. S. National Museum, have rendered invalu- 

 able assistance; Dr. Riclimond through Ins special knowledge of 

 ornithological bibliography and liis extremely usefid and very com- 

 plete card catalogue of generic and specific names, made at "first 

 hand,'' or directly from the publication in which each name was first 

 published, as well as by carefully scanning the proof sheets with par- 

 ticular reference to correctness of citations in the synonymy; Mr. 

 Riley, by copying references from various publications, but espe- 

 cially through having performed the tedious task of measuring several 

 thousands of specimens.^ 



There has been some criticism of the present work on the ground 

 that certain boolcs, local lists, and other publications have not been 

 cited in the synonymies. The omission of these is very much regretted 

 by the author, who in explanation, if not justification, would state 

 that it has been cjuite impossible for him to cover the whole field; 

 that the literature of ornithology is so vast, and increasing so rapidly, 

 that to bring the bibliography and synonymy of all the species up 

 to date and keep it so would rec^uire all the time that any one indi- 

 vidual could possibly give to it; and that since much the greater 

 part of this labor (which has justly been termed "the drudgery of 

 ornithology") has been done by the author himself, very largely in 

 his own time (which means during hours which should have been 



* The number of specimens examined during the i^reparalion of this volume is as 

 follows: 



Collection of the U. S. National Museum 4, 846 



Collection of the Biological Survey 1, 118 



Collection of the American Museum of Natural History 2, 255 



Collection of the Carnegie Museum 1, 358 



Collection of tlie Field Museum of Natural History 478 



Collection of the Academy of Natural Sciences, Philadelphia 170 



Collection of the Boston Society of Natural History 6 



Collection of the Museum of Comparative Zoology 2, 097 



Collection of the Musco Naciondl, Costa Ilica 66 



Collection of the Museum of Vertebrate Zoology, University of California. ... 4 



Collection of A. E. and 0. Bangs, Boston 1, 877 



Collection of C. H. Laukester, Cachi, Costa Rica 83 



14, 358 



