156 
Gen. LXXV. ROSTRHAMUS Less. (1830). 
Type by monotypy R. niger Less. =Herpetotheres sociabilis Vieill. 
Head not crested ; bill long and slender, the upper 
mandible hooked, the cutting edges not festooned ; 
nostrils narrow ovals, horizontal; tail about half 
as long as wing, nearly even. Size moderate. 
291. 
* +95Ia. 
Gen. LX XVI. 
Bill longer and more slender; upper mandible 
Rostrhamus sociabilis sociabilis (Vieill.), 
N.D., xviii., p. 318 (1817). [S. America : 
Corrientes et Rio de la Plata. 
Southern Everglade Kite. 
[ =R. leucopygus (Spix.)]. 
Wing ad. 325-345 mm.; entirely slaty 
black, with a brownish shade on wings ; 
base of tail and upper and under coverts 
white ; rest of tail black, with subterminal 
and subbasal brown borders, the tips 
white ; bill black; cere and feet yellow. 
Rostrhamus sociabilis plumbeus Ridgway,in 
Baird, Brewer & Ridgway, Hist. N. Amer. 
Birds, i., p. 209 (1874). ([£verglades, 
Florida. | 
Northern Everglade Kite. 
Larger; wing ad. 348-368 mm.; above 
paler ; head and throat more plumbeous ; 
vent paler, more brownish. 
Ixii., p. 38, 1918). 
S. America from 
Argentina and 
Peru to 
Colombia. 
Florida, Cuba, 
E. Mexico, 
Central 
America. 
HELICOLESTES Bangs & Penard {Bull) Me@:Zs 
Type by orig. desig. Falco hamatus Mlig. 
hooked almost to a sickle shape. 
252. Helicolestes hamatus (Illiger) in Temm., Pl. 
Col., 1., live. 2, pl. Gl, 23) {jume, 1820); 
[Brazil, type in Leyden Mus.] 
Slender-billed Kite. 
[R. teniurus Cab. =juv.] 
N. Brazil, 
Colombia, 
Dutch Guiana. 
