PREFACE.
Although nearly five hundred pages of the present volume were printed during the year 1903, the author's inability to complete the manuscript in time necessitated suspension of presswork until July, 1904; hence publication of the volume has been delayed much beyond the anticipated date.
Part I, issued in 1901, included the Family Fringillidæ (Finches) alone. Part II, issued in 1902, included the families Tanagridæ (Tanagers), Icteridæ (Troupials), Cærebidæ (Honey Creepers), and Mniotiltidæ (Wood Warblers). The present volume comprises the Motacillidæ (Wagtails and Pipits), Hirundinidæ (Swallows), Ampelidæ (Waxwings), Ptilogonatidæ (Silky Flycatchers), Dulidæ (Palm Chats), Vireonidæ (Vireos), Laniidæ (Shrikes), Corvidæ (Crows and Jays), Paridæ (Titmice), Sittidæ (Nuthatches), Certhiidæ (Creepers), Troglodytidæ (Wrens), Cinclidæ (Dippers), Chamasidæ (Wren-Tits), and Sylviidæ (Warblers). Part IV, which is about half completed, includes the Turdidæ (Thrushes), Mimidæ (Mockingbirds), Alaudidæ (Larks), Sturnidæ (Starlings), Ploceidæ (Weaver Birds), Oxyruncidæ (Sharp- bills), Tyrannidæ (Tyrant Flycatchers), Pipridæ (Manakins), and Cotingidæ (Chatterers.)
In the three volumes which have been published there have been described about twelve hundred and fifty species and subspecies, or about two-fifths of the total number of North and Middle American birds.
Acknowledgments are due for the loan of specimens used in the preparation of this volume to those individuals and public institutions mentioned in Parts I and II. The extent to which these outside sources have been drawn upon may be judged by the following statement of the number of specimens of Troglodytidæ (Wrens) alone examined in the working up of that family:
| Collection of the U. S. National Museum | 1,475 |
| Collection of the Biological Survey | 1,090 |
| Collection of the American Museum of Natural History | 407 |
| Collection of A. E. and 0. Bangs | 297 |
| Collection of William Brewster | 243 |
| Collection of the Academy of Natural Sciences of Philadelphia | 176 |
| Collection of the Museum of Comparative Zoology | 74 |
| Collection of Paul Bartsch | 32 |
| Collection of the Boston Society of Natural History (Lafresnaye types) | 14 |
| Collection of William Palmer | 10 |
| Specimens of Troglodytidæ examined | 3,818 |
Measurements in the present volume not made by the author were taken by Mr. J. H. Riley, of the Division of Birds.
Robert Ridgway.
September 14, 1904.
