304 Dr. P. L. Sclater on the Birds of the Zambesi Region. 



bill slate-blue, black at tip; iris orange; toes light 

 yellow; claws black. Magomero. 



b. (imin. § .) Iris light brown ; cere and toes light lemon. 

 Chibisa. 



c. (juv. $ .) Cere, angles of mouth, and toes light lemon. 

 Chibisa. 



This very interesting series shows that Mr. Gurney's Spizaetus 

 mjresii, described and figured in the 'Ibis' for 1862, is the 

 immature form of Spizaetus spilogaster, of which the adult is 

 sufficiently accurately figured by the Baron v. Miiller, /. c. 

 Mr. Wolfs plate in the ' Ibis ' represents the immature plumage 

 in nearly every respect, except that Dr. Dickinson's specimens 

 show still less signs of a crest than are depicted in the plate of 

 Spizaetus ayresii, and the still younger bird has the under surface 

 uniform brown, with scarcely a single indication of spots. 



In the youngest specimens the under plumage is nearly 

 uniform rich fulvous. In the next stage the spots begin to ap- 

 pear, and the under surface becomes white, densely spotted with 

 black spots, the tail being also strongly barred across. In the 

 perfectly adult the spots wear off, and the bird becomes white 

 beneath, with spots only on the breast and flanks. In this 

 plumage the tail has a broad subterminal black bar. 



4. CiRCAETUS THORACICUS, CuV. 



One example. "Iris yellow; cere very dirty cream-colour." 

 Chibisa. 



5. CiRCAETUS zoNURUS, P. von Wiirtemberg; Heughn, Ibis, 

 1860, pi. 15. p. 410. 



Three examples : — 



a. " Iris yellowish brown." Magomero. 



b. " Iris cream-colour." Chibisa. 



c. '' Iris cream-colour." Chibisa. 



This rare species of Circaetus is figured in the * Ibis,' as above 

 quoted, from v. Heuglin's drawing, with sufficient accuracy to 

 render it easily recognizable. M. Jules Verreaux's remarks on 

 the same bird (Ibis, 1862, p. 210) should also be referred to. 



6. Pandion haliaetus (Linn.). 



One example. " Iris yellow." Chibisa. 



