Order PASSERIFORMES. 
PASSERINE BIRDS, 
Bill hard and horny, never extensively membranous, softly tumid, nor 
cered; nostrils without open communication; greater wing-coverts not 
more than one-half the length of the secondaries; primaries usually ten, 
more rarely nine; rectrices twelve, rarely ten; feet adapted for perching ; 
- hind toe and claw well developed and inserted on the level of the anterior 
toes ; hind claw equal to, or longer than, the claw of middle toe; anterior 
toes three in number, never versatile, always free except when webbed 
or fused at base. 
The order Passeriformes includes nearly as many species, among 
Philippine birds, as all the other orders combined. Most of the species 
of this order are less than 200, and very few of them are more than 300, 
millimeters in length. The small birds belonging to other orders are 
extremely few. Most ornithologists consider the Passeriformes to be 
the order of highest rank among birds, chiefly because of the highly 
developed vocal powers of many of the species. In the arrangement of 
the families of this order, the T'urdidw, Fringillidew, and Corvide have 
variously been assigned to the place indicating the highest development. 
Suborders.* 
a. Tarsus with its hinder portion somewhat compressed, but the posterior edge 
ToOUNdedsanOventineten 22-2 we ee ee Mesomyodi, or Clamatores (p. 413) 
_ a’. Tarsus with its hinder portion compressed and forming a sharp edge; or else 
} the hinder face rounded and distinctly divided by transverse joints. 
4 Acromyodi, or Oscines (p. 422) 
Suborder MESOMYODTI. 
\ Characters the same as those given in the key to Suborders. 
Family PITTIDZ. 
4 Rectrices twelve; tarsus booted, or with obsolete, diagonal divisions. 
: PA part eae tke We tceece presented by the fareal envelope, ‘this division 
_ into suborders is fully justified by internal structures, but as these can not be 
examined in skins they are omitted above. 
b, Key to the suborders of Passeriformes based upon internal characters. 
a a, Intrinsic muscles of the syrinx fixed to the middle of the bronchial semirings, 
th Sueomunctes simple, small, and LeW....-...-----»-----<--0-:4s-0seece=erececrneccoene Mesomyodi 
ai a*, Intrinsic muscles of the syrinx fixed to the ends of the bronchial semirings, 
| nie muscles complex and numerous............--.----.--:-2--cenes-0adaeernanecessenes Acromyodi 
83286 413 
