BIEDS — PRIXGILLIDAK — SPIZELLINAE. 439 



a. Tliickly streaked everywhere above, on the sides, and acrosa the breast. Wing pointed ; 

 longest primaries considerably longer than the secondaries. Tail forked. 



Centronyx. — Hind claw very large ; rather longer than its digit. The hind toe 

 and claw, together, as long or longer than the middle toe and claw. Otlier toes 

 as in Passerculus. Claws gently curved. Tertials shorter than the .sucondaries. 

 Tail forked, but the lateral feathers shorter. 



Passerculus. — Hind claw as long as its digit ; the toe equal to the middle one 

 without its claw ; lateral toes falling considerably short of tlio middle claw. 

 Wings very long ; first primary longest. Tertials us long as the jjrimaries. 

 Tail forked ; feathers acute. 



PooCi'ETES. — Hind claw shorter than its digit ; the whole toe less than the middle 

 toe without its claw. Lateral toes nearly equal to the middle one, without its 

 claw. Tertials but little longer than secondaries. Tail stiffened, forked ; 

 feathers acute, outer ones white. 



b. Moderately streaked above, on the sides, and on the breast ; tlie dorsal streaks 

 broader, the others fainter than in the last. Wings short, reaching a little beyond the 

 base of the tail. Not much difference between the primaries and secondaries. Tail 

 short, graduated, and the feathers lanceolate, acute. 



CoTURXicuLUS. — Bill short ; thick. Tertials almost equal to the primaries ; trun- 

 cate at the end. Claws small, weak ; hinder one shorter than its digit. Out- 

 stretched feet not reaching the tip of the tail. Tail feathers not stiffened. (In 

 one species tail nearly equal to the wing.) 



Ammodramus. — Bill slender, small at base, and elongated. Tertials not longer 

 than the secondaries ; rounded at tlie tip. Claws large, hinder one equal to its 

 digit. Outstretched toes reaching considerably beyond the end of the stiffened 

 almost scansorial tail. 



B. — Tail longer and broader ; nearly or quite as long, sometimes a very little longer than 

 the wings, which are rather lengthened. The primaries considerably longer than the secondaries. 

 None of the species streaked beneath, and the back alone streaked above. 



a. Tail rounded or slightly graduated. 



Chondestes. — Tail considerably graduated, not emarginated. Lateral toes con- 

 siderably shorter than the middle toe, without its claw. Wings very loniT 

 decidedly longer than the tail, reaching the middle of the tail. First quill 

 longest. Head striped. Back streaked. White beneath. A white blotch on 

 the end of the tail feathers. 



ZoNOTRicHiA. — Tail moderately graduated. Wings moderate, about as long as the 

 tail, reaching about over the basal fourth of the tail ; first quill less than the 

 second to fourth. Feet large. Head striped witli black and while. Back 

 streaked. 



