272 AYES : PASSERES. — XLVL 



c. Hinder edge of tarsus not compressed, rounded and scutellate like 

 anterior edge; hind claw very long, straightish; developed pri- 

 maries !) Alaudid.e, 104. 



re. Hinder edge of tarsus compressed, forming a sharp ridge, for the 

 most part undivided. 

 (/. Primaries apparently but 9 (the first minute and displaced) ; the first 

 developed (i. e. second) primary about as long as the next; bill not 

 hooked at tip. 

 i . Bill not fissirostral, the gape little longer than the culmen ; outer 

 primary never twice as long as inner. 

 f. Bill " con i rostral," stout at base, with the commissure forming 

 a more or less distinct angle at base of bill, " the corners of 

 the mouth " drawn downward. 

 g. Bill rather long, often longer than head, without notch at tip 



or bristles at the rictus Icterid.e, 166. 



gg. Bill shorter than head, often notched near tip, and usually 



with bristles at the rictus Fringillid;e, 167. 



ff. Bill not truly conirostral (the corners of mouth not evidently 



drawn downward). 



h. Bill stout (conical in our species, the cutting edge with one 



or more lobes or nicks near its middle) ; nostrils placed 



high, exposed; (plumage chiefly red or yellow, in our 



species) Tanagridje, 108. 



hh. Bill rather slender, not conical; angle of gonys not be- 

 fore nostril. 

 i. Hind claw short and curved, mostly shorter than its toe; 

 tertials not elongate, not nearly reaching tips of pri- 

 maries Mniotiltid^e, 173. 



u. Hind claw long and straightish, mostly longer than its toe; 

 tertials much elongate, nearly reaching tips of primaries. 



MoTACILLIDJE, 174. 



ee. Bill fissirostral, — the culmen very short, the gape very broad, 

 its length more than twice the culmen; wings very acute, the 

 outer primary more than twice length of innermost. 



HlRUNDINID/E, 100. 



(Id. Primaries evidently ten, the first developed, but short, rarely half 

 the length of the next; (first primary obsolete in some Vireos, 

 known by the slightly hooked bill). 

 j. Tarsus distinctly scutellate. 



k. Tarsus not longer than middle toe with claw; bill 

 short, depressed ; (head crested ; tail tipped with yel- 

 low, in our species) Ampeltd^e, 170. 



kk. Tarsus longer than middle toe and claw (or if not, 

 other characters not as above). 



I. Bill strongly hooked and toothed at tip, somewhat 



like a hawk's bill Laniid/E, 171. 



II. Bill slightly hooked at tip; (plumage more or less 



olivaceous) Vireonid/E, 172. 



III. Bill not evidently hooked at tip. 



m. Tail feathers stiff, pointed; bill decurved. 



Certhiid.e, 176. 

 mm. Tail feathers more or less soft and rounded. 

 n. Nasal feathers directed forwards, usually cov- 

 ering the nostrils. 



