50 General Remarks on the Classification of the Passerines. 



and the primaries perfect ; but Selophaga, a Tyrannine, and Sylvicola, a Singing Bird, 

 which resemble one another in the structure of the wing and of the foot, are strikingly 

 alike, and are separated, according to Audubon, by the fact that Setophaga has the larynx 

 of Tyrannns, and Sylvicola that of the Singing Birds. It must be said, and rightly, 

 that one of the Setophagae is more allied to the Singing Birds than to the Parrots, whose 

 larynx is very different to that of them both. From these remarks I do not conclude 

 that Setophaga must be placed with the Sylvidae, but I contend that those divisions are 

 unnatural which separate Setophaga and Sylvicola, and place them in perfectly diiferent 

 orders. The same holds for Cypselus and Ilirundo. It is not right to place Cypselus 

 and HiruTulo in one family ; but these Swallows are not so far separated from one another, 

 that they can be placed in perfectly different orders. 



It is, then, now thoroughly proved that the Singing Birds cannot be separated, as an 

 order, from the rest of the Passerines. There is only one large division oi Itisessores or Passer- 

 ines which must also include the Scansores. This order of Insessores includes birds with the 

 most various supply of vocal muscles, as well as birds which do not possess these muscles. 

 They pass imperceptibly into one another. In Upnpa the lateral muscle of the trachea 

 is inserted into the first, and slightly moveable, half-ring of the bronchus, and it is only 

 a slight step from those in which it does no longer reach the bronchus, as in Prionitis, 

 Opisthocomus, Biicco, Trogon, Rhamphastos, Pteroglossiis, Corythaix, and Chizacris. In these 

 birds, however, there is not wanting that most general condition for the formation of 

 voice — the possession of vibrating folds of membrane between the most moveable half-rings. 

 Some have, also, further elements of it, as Prionitis, which has a very large cartilago 

 aryiaenoidea of the memhrana tympaniformis attached to the lower larynx. 



It is a further qiitestion, whether we can divide the Insessores, as an order, according 

 to their larynges. 



If the Picarii and Oscines are not orders of birds, they may perhaps be tribes of 

 an order, and the same question may be asked about the Tracheophones. If these families 

 may be divided into three sections, then we get the following series : 



Okdo Insessores. 



Tribus I. Oscines s. Polymyodi. Singing Birds. 



Lanidae. Sturnidae. 



Muscicapidae. Meliphagidae. 



Turdidae, , Cinclidae. 



