136 Mr. Howard Saunders on Sexual Variations in 



part is of a nearly uniform whity brown colour with greyish 

 tips to the hairs, whiter beneath, and with a small, round, 

 white dorsal spot. 



III. The lower jaw not Jcnoivn. 



4. Dendrohyrax Blainvillei, Gray, Hand-list, pi. xi. fig. 3. 



Orbit incomplete behind ; intermaxillary bone square, trun- 

 cated behind ; lower side of orbit much produced, with a thick, 

 rounded edge and a large concavity on the underside, as in 

 D. dorsalis. 



Africa. 



XVIII. — On Sexual Variations in the Nestling-Plumage of the 

 Booted Eagle (Nisaetus pennatus). By Howard Saunders, 

 F.Z.S. &c. 



The ordinary adult plumage of the Booted Eagle is so well 

 known that it is unnecessary to do more than remark that the 

 upper parts in general are of an umber-brown, whilst the 

 underparts are of a buff or creamy white, sometimes deepening 

 into fawn-colour, and with striations more or less distinct down 

 the shafts of the feathers of the throat, breast, abdomen, and 

 flanks. That this plumage is common to both sexes has 

 been abundantly proved by numerous carefully sexed speci- 

 mens obtained of late years from various localities between 

 Spain on the west and India on the east. But with regard 

 to the plumage of the immature bird there has existed some 

 difference of opinion, although most naturalists have stated 

 that it has the underparts of a dark colour. Mr. R. Bowdler 

 Sharpe, in his recently published ' Catalogue of the Accipitres 

 in the British Museum,' p. 254, describes the underparts of the 

 young as " entirely dull brown;" but, on the other hand, Dr. 

 Jerdon, in his ' Birds of India,' vol. i. p. 64, has described 

 an immature bird as having a light breast. Herr A. v. Pelzeln, 

 ao-ain ( l Ibis,' 1868, p. 305), mentions a young bird just able 

 to fly as " underneath brown :" and subsequently Dr. Jerdon 

 ( l Ibis ' 1871, p. 246) was inclined to modify his former 

 opinion ; but as the specimens there alluded to are the ones I 

 am about to describe, it is needless to recapitulate his views. 

 Mr. Hume, however ('Rough Notes,' p. 184), hazarded the 

 opinion that the dark plumage was the adult stage (!), ap- 

 parently basing this upon an instance of a female in the 



