448 



NORTH AMERICAN BIRDS. 



a. Points of mandibJes overlapping. 

 Curvirostra. Tarsus shorter than middle toe. Bill much compressed, 

 elongate falcate, with the points crossing like the blades of scissors. Claws 

 very large ; lateral extending beyond the base of the middle. Colors red or 

 gray. Streaked in juv. 



b. Points of mandibles not overlapping. 

 .ffigiothus. Tarsus equal to the middle toe. Bill very acutely conical ; out- 

 lines and commissure perfectly straight. Lateral toes reaching beyond the 

 base of the middle one. No ridge on the side of the lower mandible. 

 Streaked ; a crimson pileum (except in one species). 



Leucosticte. Culmen shghtly decurved; commissure a little concave. 

 Bill oljtnsely conical ; not sharp-pointed. A conspicuous ridge on the side 

 of the lower mandible. Claws large; the lateral not reaching beyond the 

 base of the middle one. Colors red and brown. 

 I>. Hind claw much the largest ; decidedly less curved than the middle anterior 

 one. Tarsus longer than the middle toe. Lateral toes equal ; reaching about to 

 the base of the middle claw. Hind toe as long or longer than the middle one. 

 Bill very variable ; always more or less curved and blunted. Palate somewhat 

 tuberculate ; margins of lower jaw much inflexed. Tail slightly emarginate or 

 even. WinL's (mo half longer than the tail. First quill as long as the second. 

 Plectrophanes. Colors black and white. With or without rufous nape or 

 elbows. Much white on tail. 



Genu.s HESPERIPHONA, r.oNAP. . 



Hesperiplwna, Bonap. Comptcs Rendus, XXXI, Sept. 1850, 424. (Type, Fringilla vcspcr- 

 thia.) 



Gen. Char. Bill largest and stoutest of all the United States fringilline birds. Upper 

 mandible much vaulted ; culmen nearly straight, but arched towards the tip ; commissure 

 concave. Lower jaw very large, but not liroader than the upper, nor extending back, as in 



167TO 



18597 



16770, Hesperiphona vesprrtina. 18597, Cbtcolhraustes vulgaris. 



Guiraca ; considerably lower than the upper jaw. Gonys unusually long. Feet short ; tarsu.i 

 less than the middle toe ; lateral toes nearly equal, and reaching to the base of the mi Idle 



