FALCONINJE. 331 



rt n . Primaries exceeding secondaries by 



more than length of tarsus. 

 a 1 . No elongate occipital crest. 

 a\ Culmen straight at base, then 



curving AQUILA, p. 332. 



b\ Culmen curving from cere *. . HIERAETUS, p. 342. 

 b\ An elongate occipital crest ; ab- [p. 345. 



domen chestnut in adults LOPHOTBIORCHIS, 



//'. Primaries exceeding secondaries by 



less than length of tarsus SPIZAETUS, p. 348. 



6". Claws but little curved, inner longer 



than hind claw ICTINAETUS, p. 346. 



b'. Tarsus not feathered throughout. 

 c". Tarsus reticulated throughout, no 



scutellse broader than high. 

 c 3 . Tarsus long, more than 1| times 



length of bill from gape to point. 

 c 4 . Scales on tarsus subequal 

 throughout : size of bird large. 

 (Serpent-Eagks.) 



c\ Head not crested CIRCAETUS, p. 355. 



d?. Feathers of nape and sides of 

 neck lengthened to form a 



crest SPILORNIS, p. 357. 



r/ 4 . Scales in front of tarsus larger 

 than behind : size small. (Buz- 

 zard Eagles.) BUTASTUB, p. 362. 



d 3 . Tarsus short, less than 1 times 



length of bill from gape , . ELANUS, p. 379. 



d". Tarsus with some scutellae broader 



than high. 



e 3 . Size large: tarsi very long and thick, 

 scutellated in front and either 

 reticulated behind or irregularly 

 scutellated ; scales beneath toes 

 rough and pointed. (Sea-Eagks.) 



e*. Claws grooved beneath HALIAETUS, p. 366. 



/ 4 . Claws rounded beneath POLIO AETUS, p. 369. 



f* t Size moderate : tarsus scutellated 



in front but not behind. 

 ff*. Tarsus short; bill from gape 

 more than half tarsus. (Kites.) 

 e 5 . Tail slightly rounded at the 



end HALIASTUB, p. 372. 



/ 5 . Tail forked MILVTJS, p. 374. 



h\ Tarsus long ; bill from gape less 



than half tarsus. (Hamers.) CIRCUS, p. 380. 

 g 3 . Size moderate or small : tarsus 



scutellated behind. 

 i 4 . Bill from gape half length of 

 tarsus or less. (Hcncks.) 



* This distinction is very unsatisfactory. Generally Hieraetus 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. chrysaetm. 



