h''. Crest-feathers rounded ; vriug ex- 

 ceeding tip of tail by more than 



length of tarsus 52. Helotarsus, p. 299. 



t'. Crest-feathers lanceolate ; wings 

 reaching nearly or quite to tip 



of tail 53. HAiiAETUS, p. 301. 



t*. Eyebrow bare 54. Gypohierax, 



/■'". Nostrils circular, with bony margin p. 312. 



all round 55. Haliastxjb, p. 312. 



g'". Nosti-ils oblique, generally closed in 

 with a superior membrane, so as to 

 render the nasal opening almost 

 linear in character. 

 k^. Tail forked, outer tail-feather long- 

 est. 

 k"". Distance between tips of pri- 

 maries and tips of secondaries 

 equal to fork of tail, 

 c^. Wing extremely long, exceed- 

 ing length of tail by more 

 than twice the length of tar- 

 sus 56. Elanoides, p. 317. 



d^. Wing very long, but not ex- 

 ceeding length of tail by twice 



length of tarsus 57. Nauclertts, p. 318. 



P' Distance between tips of prima- 

 ries and tips of secondaries 

 gi-eater than difference between 

 longest and shortest tail-fea- 

 ther (i. e. fork of tail). 

 e^. Distance from angle of mouth 

 to anterior margin of nostril 

 greater than distance from 

 latter point to tip of beak . . 58. MiLvrs, p. 319. 

 f^. Distances as aboTe measm-ed 



equal 59. Lophoictinia, 



y^. Distance from angle of mouth p. 326. 



to nostril less than distance 

 from latter point to tip of beak 60. Rostheamus, 

 /'. Tail rounded, outer feather shorter p. 327. 



than middle one. 

 «i*. Ridge of bill (without cere) great- 

 er than half of middle toe (with- 

 out claw). 



A*. Loral space bare 61. Leptodon, p. 329. 



t*. Loral space feathered. 



a'. Wings reaching right to end 

 of tail. 

 a^. Bare part of tarsus in front 

 gTeater than half of mid- 

 dle toe (without claw) . . 62. GYPOICTI^^A, 

 h^. Bare part of tarsus in front p. 335. 



less than middle toe 



(without claw) 63. Elanus, p. 336. 



b'. Wings falling short of tail 

 by at lea«t as much as, or 



b2 



