﻿110 ON THE CLASSIFICATION OF BIRDS. 



have broad and simply pointed tails (as in S. canifrons), 

 while in others (S. ruficeps, fig. 57« a) the points are 

 lengthened and slightly stiffened : between this last form 

 and that seen in Certhia familiaris (b) comes the cinna- 

 mon creeper, SynaUaxis cinnamominus (c), which is a 

 true Synallaxis, beginning to assume the tail of Certhia. 

 The nuthatches again are decided climbers, and yet 

 their tails are of the usual construction. On the other 

 hand, there are instances of birds out of the circle of the 

 Scansores, yet representing that order, which exhibit 

 some of the essential characteristics of a scansorial tail. 

 That noble grouse, the cock of the plains (Centrocircus 

 urophasianus)* , exemplifies this in a remarkable manner, 

 the feathers being lance-shaped, stiff, and terminating 

 in acute points ; of the same structure, in short, as those 

 of Certhia familiaris. The maize bird of America, also, 

 (Dolicony.v oryzivorus) has a completely scansorial tail, 

 shaped precisely like those of Dendrocolaptes , with this 

 difference only, that it is less rigid, and the shaft is not 

 thickened. Very many other perching genera have either 

 the naked acuminated tips of Lochmia and Synallaocis, 

 or the tip of the shaft forms a little mucro, or point. 

 We find this latter peculiarity among the cockatoos, 

 (Plictolophince), as one of the many analogical characters 

 which show them to be the representations of the 

 Scansores, in the circle of the parrots (Psittacidcp). 



(102.) A divaricated tail is the last modification of 

 this most variable member which we shall specifically 

 name. Its form is intermediate between the even, and 

 the forked structure. All the feathers, in fact, are of 

 equal length, but when the tail is closed, they seem to 

 be divided in the middle, into two equal divisions, the 

 points of which turn outwards in contrary directions, and 

 thus, on a casual inspection, have every appearance of 

 being slightly forked or divided. AVhen, however, the 

 tail is spread, the equality of the feathers is at once per- 

 ceived. The feathers of nearly all tails, thus constructed, 

 have their tips pointed, and as this form is chiefly found 



* North. Zool. vol. ii. pi. 58. 



