X INTRODUCTION 



ernmental surveys and explorations of the "Great West" during the first 

 three quarters of the nineteenth century. 



Two of our types possess a peculiar interest in being unique of their kind. 

 These are Tringa cooperi Baird, a sandpiper taken on the coast of Long 

 Island on May 24, 1833, and Emberiza Townsendii Audubon, a bunting 

 collected in Chester County, Pennsylvania, on May 11, 1833. Neither bird 

 (either or each may represent a mutation, a hybrid of uncertain parentage, 

 or the last of its dying race) has ever been seen again and, were the speci- 

 mens not now extant, each would be considered a chimerical species. 



To all those, too numerous to name, who have assisted me in my researches, 

 and to my wife, Stella Leche Deignan, who has assisted me in the tedious 

 task of reading the proofs, I now extend my thanks. 



