142 ZOOLOGY BIRDS. 



to take the field has generally been too late for any investigations into the 

 nesting habits of the birds, and for this reason the notes relative to their 

 peculiarities at this period are nearly wanting. 



The classification and nomenclature followed for the Land Birds is that 

 adopted by Baird, Brewer, and Ridgway, in their recent work on "North 

 American Birds"; for the Water Birds, that given by Dr. Cones in his 

 " Check List" is used. 



As being less cumbersome, the technical names have been followed 

 only by the original describer's name, this being inclosed in parentheses when 

 not also the authority for the nomenclature. In many cases, each species 

 is followed by a complete list of the birds collected, the date and exact 

 locality of their capture, with the collector's name, this being a ready method 

 of indicating with precision the locality from which they were derived ; while 

 a large number of measurements have also been taken, where the rarity of 

 the species has seemed to make this a matter of importance, and also when 

 the specimens have been collected at widely separated points, to show the 

 amount of variation produced by climatic and other causes, as also the 

 amount of individual variation. In many cases, however, it has not been 

 thought advisable to present a full enumeration ; the context sufficiently 

 showing the results of the investigations, of which the specimens are merely 

 the indices. Probably not more than one-half of the three thousand birds 

 for the number of the four years' work reaches quite to this figure are 

 thus mentioned. 



In the preparation of the synonymatic lists, endeavor has been made 

 to bring together only such references as have a bearing more or less directly 

 upon the region embraced by our investigations, and, within this scope, to 

 make them as nearly complete as possible ; the value of such references in 

 their bearing upon the facts of geographical distribution being well known. 

 In this part of the work, the labor has been much, lightened by the admirably 

 full tallies given by Dr. Cones in his recent work on the " Birds of the 

 Northwest." To this gentleman, and also to Mr. Robert Ridgway, of the 

 Smithsonian Institution, and to Dr. H. C. Yarrow, I am under obligations 

 lor much kindly advice and assistance. 



