'22^5 F^ixcoKii)^. 



a*. No elongated crest ; ridge of bill 

 (■without cere) greater than 

 inner toe (without claw) mea- 

 sui'ed from extremity of tarsal 



feathers 39. Aquila, p. 232. 



b^. No elongated occipital crest ; in- 

 ner toe measured as above equal 



to cii-ciuuference of culmen . . 40. Nisaetus, p. 249. 

 c*. Crest long and Tredge-shaped, 

 longer than outer toe and claw; 

 circumference of culmen deci- 

 dedly less than length of inner 



toe 41. Lopho'teioechis, 



b^. Claws nearly straight ; the circum- p. 255. 



ference of inner claw exceeding 

 the length of outer toe even with 



its claw included 42. Neopus, p. 256. 



c*. Claws rounded and powerful ; the 

 circumference of inner claw about 

 equal to the length of outer toe 



and claw 43. Spiziastub, p. 258. 



b'". Distance between tips of primaries 

 and tips of secondaries less than 

 length of tarsus. 

 d^. Crest-feathers sometimes fidly de- 

 veloped, sometimes absent ; wings 

 short, falling short of tail by more 



than length of crest 44. Spizaetus, p. 259. 



e*. Crest-feathers extremely long and 

 pendent, far exceeding in length 

 the distance by which the wings 



fall short of the tail 45. Lophoaetus, p. 274. 



//. Tarsi bare on lower portion. 



c". Bare part of tarsus equal to or longer 

 than middle toe without claw. 

 c'". Nostrils with osseous margin. 

 /^. Nostrils circular. 



(P. Tarsi ti-ansversely plated in front. 46. Astueinula, p. 275. 



e'. Tarsi reticulate in front 47. IIeepetotheres, 



(/■'. Nostrils perpendicular ovals. p. 277. 



/°. Crest-feathers lanceolate in shape, 

 about equal in length to middle 

 toe with claw. 

 a^. Wing short, less than once and 



a half the length of tail .... 48. Deyoteiohchis, 

 ¥. Wing long, more than once and p. 278. 



a half the length of tail .... 49. Ciecaetus, p. 280. 

 ff^. Crest-feathers rounded, longer 



than middle toe with claw. . 50. Spu-oenis, p. 287. 

 d". Nostrils oval, with a superior mem- 

 brane 51. Butastur, p. 294, 



d". Bare part of tarsus less than middle toe 

 without claw. 

 e'". Nostrils more or less perpendicular 

 ovals, with bony margin all round. 

 /('. Eyebrow feathered. 



