FALCONING. ^^^ 



a^. Primaries exceeding secondaries by 

 more than lengtli of tarsus. 

 ff'. No elongate occipital crest. 

 n\ Culmen straight at base, then 



curving Aquila, p. 3-^2. 



b'. Culmen curving from cere * . . Hieeaetus, p. 6iZ. 



/>* An elongate occiintal crest ; ab- LP- ^^^• 



domen chestnut in adults ...... Lophotriorchis, 



b'-'. Primaries exceeding secondaries by 



less than length of tarsus SpizAiixus, p. 348. 



6". Claws but little curved, inner longer 



than hind claw Ictinaetus, p. ^4b. 



b'. Tarsus not feathered throughout, 

 c". Tarsus reticulated throughout, no 

 scutellse broader than high. 

 c\ Tarsus long, more than 1^ times 

 length of bill from gape to point, 

 c*. Scales on tarsus subequal 

 throughout : size of bird large. 

 (Serpent-Eagles.) ,. _ 



c\ Head not crested Circaetus, p. 355. 



rf\ Feathers of nape and sides of 

 neck lengthened to form a 



crest ... 7 Spilornis, p. 357. 



dK Scales in front of tarsus larger 

 than behind: size small. {Buz- 



zard Eagles.) Butastur, p. 362. 



di". Tarsus short, less than 1^ times 



length of bill from gape Elanus, p. 379. 



d". Tarsus with some scutellte broader 

 than high, 

 e^. Size large: tarsi very long and thick, 

 scutellated in front and either 

 reticulated behind or irregularly 

 scutellated; scales beneath toes 

 rough and pointed. {Sea-Eagles.) 



e\ Claws grooved beneath Haliaetus, p. 3bb. 



f\ Claws rounded beneath Polioaetus, p. 369. 



/^ Size moderate : tarsus scutellated 



in front but not behind. 



g\ Tarsus short; bill from gape 



more than half tarsus. {Kites.) 



e\ Tail slightly rounded at the 



end Haliastub, p. 372. 



f\ Tail forked'. ".'.". Milvus, p. 374. 



h\ Tarsus long ; bill from gape less 



than half tarsus. {Harriers.) Circus, p. 3«U. 

 ^^ Size moderate or small : tarsus 

 scutellated behind. 

 {*. Bill from gape half length of 

 tarsus or less. (Hawks.) 



* This distinction is very unsatisfactory. Generally Hieractus may be 

 distinguished by having the middle toe longer than the bill from gape whereas 

 in Aquila the latter is the longer, but this does not hold good with Aquila 

 maculata and A. chrgsaetiis. 



