PASSERES. 321 



ORDER PASSERES. PERCHING BIRDS. (Pages.) 



Families. 



1 . Tarsus cylindrical, or with hinder portion rounded; encircled with a single 



horny envelope (divided into scutellse anteriorly and on outer side), this 

 sometimes extending all round (though separated by a seam along inner 

 side), but often widely separated on inner side or behind (or both), the 

 intervening space occupied by granular scales, reticulations, or plain naked 

 skin. (Suborder Clamatores.} 

 b l . Inner toe with basal phalanx united to that of middle toe ; posterior face of 



tarsus reticulate Cotingidse. (Page 323.) 



6 J . Inner toe entirely free at base from middle toe ; posterior face of tarsus not 

 reticulate Tyrannidse. (Page 326.) 



2 . Tarsus compressed behind, with comparatively sharp posterior edge (or else 



hind-claw longer than its digit; and straight), the enveloping membrane 

 divided into two or three longitudinal segments, which may be either divided 

 into transverse segments, or scutellae, or fused into continuous plates. (Sub- 

 order Oscines.*) 



b l . Posterior half of tarsus not compressed, but rounded, and divided into dis- 

 tinct segments, or scutellse, like the anterior half. 



Alaudidse. (Page 346.) 

 2 . Posterior half of tarsus compressed, with two lateral plates uniting behind 



in a comparatively sharp ridge, and for the most part undivided. 

 c l . Primaries apparently only 9 (the 10th being exceedingly rudimentary), 



the tip of the bill not hooked. 

 d 1 . Bill variously formed, but gape never twice as long as culmen ; 



outer primary never twice as long as innermost. 

 e 1 . Bill straight. 



f l . Bill conoid ; if slender, the angle of the gonys forward of 



the nostril. 

 g 1 . Bill without notch, and without bristles at gape. 



Icteridae. (Page 365.) 

 g*. Bill notched, and with bristles at gape. 



A 1 . Nostrils concealed by feathers, or pointed an- 

 teriorly and overhung by a distinct scale 

 or horny membrane, or else base of cutting- 

 edges forming a distinct angle. 



Fringillidae. (Page 382.) 



h*. Nostril exposed, rounded anteriorly, without 



distinct overhanging scale or membrane, and 



cutting-edges of bill not forming a distinct 



angle at the base.. Tanagridae. (Page 453.) 



41 



