CIRCUS. Al ta | 
Suborders. 
a, Claws less curved, that of middle toe describing much less than a semicircle; 
OUBER HOC NO’, TEV ErsiD le (oi sie asco cin cn cp ceceeccdomerninae eteauebanatane Accipitres (p. 211) 
a’. Claws greatly-curved, that of middle toe describing a full semicircle; outer toe 
POVGLSID Op setesttcc ese osecnteeer eae pl athe coho ahs Sees ee Pandiones (p. 244) 
Suborder ACCIPITRES. 
This suborder includes all the hawks and eagles except the fish hawks 
of the genera Pandion and Polioaétus; its members are distinguished by 
having the outer toe not reversible and all of the claws moderately curved, 
that of middle toe describing much less than a semicircle; concave or 
under side of each claw hollowed or grooved instead of rounded. 
Family FALCONIDA. 
Characters same as those given for the Suborder. 
Subfamilies. 
a. Tarsus and toes longer and more slendev....................-......--- Accipitrine (p. 211) 
a7, ‘Larsus and toes shorter/and stouter! 2.2. eee. Aquilins (p. 222) 
, Subfamily ACCIPITRIN 2. 
In external characters this subfamily differs very little from Aquiline ; 
its members are weaker with body and legs more slender, wings and tail 
longer, and plumage less compact. 
Genera. 
a’, Hinder aspect of tarsus with many hexagonal scales; wing, 300 mm. or more. 
Circus (p. 211) 
a’, Hinder aspect of tarsus without hexagonal scales; wing, 200 mm. or less. 
b*. Middle toe without claw about twice the culmen from anterior margin of cere. 
Astur (p. 216) 
b*. Middle toe without claw more than twice the culmen from anterior margin 
Of Ceres ee ao A eee Eee Oh phn cok ee RC ae ae lh Accipiter (p. 219) 
Genus CIRCUS Lacépéde, 1799. 
Bill moderate or weak, somewhat compressed; margin of upper man- 
dible slightly sinuate but not toothed; wing very long and pointed, first 
primary short, about equal to sixth; secondaries much shorter than 
primaries; tail long, slightly graduated or nearly square; tarsus long 
and slender, feathered at the base and overhung for about half its length 
by the long thigh-feathers; front of tarsus with transverse plates, sides 
and most of the hinder aspect with hexagonal scales; toes long, nails 
long and much curved ; behind ear-coverts and sometimes across the throat 
a “ruff” of short, rather stiff feathers, most conspicuous in the young 
of melanoleucos and not very evident in the other species. 
