174 Bulletin American Museum of Natural History. [Vol. .XXXVI, 



yet been recorded, but I can affirm from personal experience that the call of 

 Colinus nigrogularis of Yucatan and of Colinus cristatus leucotis of Colombia 

 is essentially the familiar " Bob-white " of Colinus virginianus. The voice 

 of the southern bird lacks the volume of that of the northern one, but the 

 notes and their peculiar quality are the same in all three. In view of all 

 these facts, I feel that the actual relationships of the species of this group 

 are more nearly expressed by referring them all to the genus Colinus. 



To illustrate further what I feel to be the evils of unwarranted generic 

 separation, there is found in southern South America (Bolivia, southern 

 Brazil, Argentina and Chile) a group composed of those species of small 

 black and white woodpeckers, the close relationship of which to the Downy 

 Woodpecker is obvious, and which have generally been considered as con- 

 generic with that species. They all have the back barred as in Dryobates 

 scalaris, of the southwestern United States and Mexico, and the more 

 western species {lignariu£) has the underparts heavily streaked. Since, 

 however, in this respect it differs from the south Brazilian species cancellatu^, 

 more than does that species from scalaris, this cannot be considered a charac- 

 ter of generic importance. The southern birds, it is true, have all, instead 

 of only the lateral tail-feathers barred as in our northern species; but 

 although I believe that pattern of coloration is often a much better generic 

 character than differences of degree in the shape of bill, relative length of 

 wing, etc., no one, I think, would claim that this difference in the pattern of 

 tail-marking would warrant generic separation. The only 'structural' 

 differences said to exist between the North American and South American 

 species of these Woodpeckers, are to be found in the' relative length of the 

 primaries and secondaries, which results in giving the southern birds a more 

 'rounded' wing. On the basis of this character it is, therefore, proposed 

 to segregate them in the genus Dydiopicyus Bonap., a proceeding which 

 would conceal what I believe to be the generic relationships of the Downy 

 Woodpeckers of South America and North America, a relationship of high 

 importance zoogeographically since in the territory lying between Bolivia 

 and western Panama no form of this group is known to occur. A broader 

 view of this case would involve a consideration of the generic relationships 

 of the New World and Old World forms of these Woodpeckers, but into 

 this phase of the subject I am not now prepared to enter, and I here insist 

 only on the congeneric affinities of the New World species. That the call- 

 note of Dryobates lignarius of western Argentina and Chile resembles the 

 familiar peek of our Downy Woodpecker is of significance in this connection. 



This is not the only case in which generic separation would conceal, so 

 far as nomenclature is concerned, the exceedingly significant fact that 

 species of the same group are present in what may be roughly termed 



