BIRDS — FULIGULIXAE. 787 



Btjcephala. — Bill shorter than the head ; about equal to the tarsus ; compressed 

 and somewhat tapering. Nostrils near the middle of the bill. Nail rather 

 larger than in Fuligula. Tail longer and more pointed ; about half the wing. 

 Head, neck, and back black ; the former with green or purple reflections. 

 Under parts, including crissum, lower part of neck, scapulars, large patch on 

 the wings, and cheeks, white. Axillars and inside of wing blackish. 

 b. Bill with the nail very broad, occupying the entire tip, and scarcely distinguishable 

 by reason of its fusion with the rest of bill. 



HiSTRioNicus. — Bill shorter than head or tarsus ; elevated at base ; narrowing 

 rapidly. Nostrils reaching the middle of the bill. Tertials bent outwards. 

 Bill with a membranous expansion overlapping its base. Color plumbeous ; the 

 only white being in the form of spots or bands on the outer surface. 

 PoLYSTiCTA. — Bill somewhat similar, but broader at the tip and more truncate. 

 Upper angle of base of bill not extending back as far as the lower. Feathers 

 of head close set and velvety ; almost erect. Tertials much bent outwards. 

 Body dusky ; lighter on the sides. Head, wings, and scapulars with much 

 white. Inside of wing white. Head tinged with grass green. 

 B. Side of bill without any distinct acute angle at the base above, or, if present, it does not 

 reach as far back as the angle of the mouth, the feathers extending forward, and further 

 above than laterally, (so as to obliterate the angle more or less;) the lateral outline of feathers 

 more or less oblique. 



a. Bill without any peculiar gibbosity at the base. 



Harelda. — Bill shorter than the head, or than tarsus ; high, tapering to the tip, 

 where the nail occupies the terminal portion. Nostrils linear, in the posterior 

 half of the bill. No membrane at the end ; the feathers of head normal. Tail 

 feathers excessively long and pointed ; equal to the wing. Color black and 

 white. Breast and wings on both surfaces black ; the latter without any white ; 

 rest of under parts, including crissum, white. 

 Camptolaemus.— Bill broad and depressed ; the sides parallel to the end, which is 

 bordered by a membranous skin. Nostrils in the, basal third of bill. Feathers 

 of cheeks stiffened. Tail short, rounded ; two-fifths the wing. Body and 

 quills black ; rest of wings, head, and neck, white. A streak on top of head 

 and a collar on neck black. 

 Lampronexta. — Bill depressed, rather narrow ; longer than tarsus. Feathers of 

 forehead extending on the culmen beyond the nostrils, and thence passing 

 obliquely in a gentle curve to the angle of the mouth, across the posterior 

 portion of the nasal groove. Tail short. Above white ; beneath black. A 

 quadrilateral black outline round the eye ; occiput and nape green. 

 h. Bill much swollen or gibbous at the base ; then much depressed, and broad. Nail 

 very large, forming the tip. Nostrils anterior to the middle of the bill. 



OiDEMrA. — Feathers of forehead extending only to base of gibbosity ; those of side 

 of head sloping gently forward. Nostrils linear, midway between feathers of 

 forehead and tip of bill. Color entirely black. 



