374 



BULLETIN OF THE 



dominance of the black in those in which portions of the plumage are 

 mottled with this color, and the greater breadth of the dark transverse 

 bars, and the correspondingly diminished breadth of the alternating 

 lighter ones. To illustrate this point more fully, I herewith append a 

 list of some of the so-called species of American birds that have been 

 specifically separated by different authors from their northern repre- 

 sentatives, but which are in reality only the extreme southern forms of 

 species previously well known, with which they were considered by the 

 older writers to be specifically identical, the most of them having been 

 separated within the last ten or fifteen years : — 



Accipiter Gundlachi, separated from Accipiter Cooperi. 

 Accipiter fringilloides, " Accipiter fuscus. 



Falco dominicensis, 



cinnamominus et ' " Falco sparverius. 



Mimus polyglottus. 



Seiurus noveboracensis. 

 Thryothorus ludovicianus. 

 Dendrceca aestiva. 



Chordeiles popetue. 



Antrostomus vociferus. 

 Icterus spurius. 



Sturnella ludoviciana. 



Quiscalus purpureus. 

 Corvus americanus. 

 Ortyx virginianus. 

 Campephilus principalis. 

 Colaptes auratus. 

 Butorides vircscens. 

 Actiturus Bartramius. 

 Macrorhamphus griseus. 

 Charadrius melodus 



Larus argentatus. 



Sparveroides, etc. 

 Mimus Gundlachi ") 



et Hillii, etc. ) 



Seiurus ludovicianus, 

 Thryothorus Berlandieri, 

 Dendrceca Gundlachi, etc. 

 Chordeiles minor et ") 



Gundlachi, etc. > 

 Antrostomus cubanensis, 

 Xanthornus affinis, 

 Sturnella hippocrepis et | 



mexicana, ) 



Quiscalus baritus, 

 Corvus minuttts, 

 Ortyx cubanensis et texanus, 

 Campephilus Bairdii, 

 Colaptes chrysocaulosus, 

 Butorides brunnescens, 

 Actiturus longicaudus, 

 Macrorhamphus scolopaceus 

 Charadrius tenuirostris, 

 Larus argentatoides et *> 



Smithsonianus, ) 



In other cases the arctic forms, or the northern types, having been 

 discovered subsequently to the southern ones, these have been described 

 a3 specifically distinct from the latter. The Bucephala islandica, sep- 



