34 
ON THE CLASSIFICATION OP BIRDS. 
crest, which can barely be discerned in the preserved skin. 
Very many of those humming birds, whose crown is 
particularly brilliant, have this slight indication of a 
fan-shaped crest, particularly the ruby-topaz*; and it 
may even be detected in the violet-eared species, t 
When fully developed, the featlicrs are so disposed that 
they radiate from the hinder part of the head, and 
assume the appearance of a fan, the last series being 
considerably lengthened : the featliers are thus spread 
out horizontally, and not, as in the last, perpendicularly ; 
and they are always broad and rounded, instead of nar- 
row and pointed. The Harpyin destructor %, or destroy- 
ing eagle of Brazil, the Bacha of Le VaiUantJ (another 
eagle of Africa), and the secretary vulture of the Cape, 
all possess the sort of crest we are now describing; but 
in no bird is it so fully or so beautifully developed as 
in the royal tody of Brazil [j {jig. 13.), the size of the 
crest being really enormous 
in proportion to that of the 
bird, and assuming an ap- 
pearance, when fully ex- 
panded, very analogous to 
that of the tail of the pea- 
cock. Sometimes, although 
the feathers are scarcely 
longer than the others, they 
are of a different colour, so 
as to produce a conspicuous 
semicircular band : in the 
six-shafted Paradise bird this band has a striking effect, 
from the splendid metallic gloss of the feathers com- 
posing it; while in the My'iagra carulea, or azure fly- 
catcher of IndialT, it resembles a crescent of black velvet. 
(43.) Of lanceolate or pedunculated crests, there are 
* TrochUus moschitusy Braz. Birds, vol. i. pi. 30. 
f Trockilus aurititSf ibid. pi. 29. 
t Reprcspnted in the vignette to this volume. 
& Ois. d’Afrique, vol. i. pi. 15. 
II Me^alophiis re^ius, Braz. Birds, vol. ii. pi. 51, 52. 
1 Le Vaill. Ois. d’Afrique, pi. 153. 
