ANALYSIS OF THE TWO EDITIONS. 



THE original edition of the "Check List" ostensibly enumerates only 635 species 

 of North American Birds. This is owing to the fact that only full species are num- 

 bered, the many subspecies being given as a, b, &c., and some names being inter- 

 polated without corresponding numbers, both in the body of the list and in the 

 Appendix. By actual count there are found to be, in the body of the list, 750 ; to 

 which 28 are added in the Appendix : 750 + 28 = 778. 



First, with regard to subtractions. It is in gratifying evidence of the general 

 accuracy of the original list, that it is found necessary to remove only ten (10) 

 names. Four of these are extra-limital ; six are mere synonyms. The following 

 is the 



LIST OF SUBTRAHEND NAMES. 



1. JEgiothus fuscescens. Summer plumage of jE. linaria. 



2. Centronyx ochrocephalus. Fall plumage of Passerculus bairdi. 



3. Sphyropicus williamsoni. Male of S. thyrotdes. 



4. Lampornis mango. Extra-limital. 



5. Agyrtria linnaei. Extra-limital. 



6. Momotus coeruleiceps. Extra-limital. 



7. Ibis thalassina. Young of Plerjadis <juaranna. 



8. Ardea wuerdemanni. Dichromatism of A. occidentalis. 



9. Sterna " longipennis." Meaning S. pikii Lawr. Young of S. macrura. 

 10. Podiceps cristatus. Extra-limital, as far as known. 



On the other hand, the numerous accessions to the list are in no less gratifying 

 evidence of the progress of our knowledge. There are no fewer than one hundred and 

 twent}- additions to be made. The large majorit.y of these are bonafide species, and 

 actual acquisitions to the North American list, being birds discovered since 1873 in 

 Texas, Arizona, and Alaska, together with several long known to inhabit Green- 

 land. It may be here remarked that although the Greenland Fauna has long been 

 usually claimed and conceded to be North American, yet the full list of Greenland 



