FEMALE INDIGO FINCH. 
141 
it. These species have, it is true, a hill somewhat 
different from that of the typical Coccothraustes , 
being much less thick and turgid, and higher than 
broad ; the upper mandible being larger than the lower, 
and covering its margins entirely, compressed on the 
sides, making the ridge very distinct, (not rounded 
above,) and curved from the base, but at tip especially : 
the margins of both are angular. 
34 . FRINGILLA CYANEA , BONAPARTE. 
FEMALE. INDIGO FINCH. 
BONAPARTE, PLATE XV. FIG. IV. 
The remarkable disparity existing between the 
plumage of the different sexes of the common indigo 
bird renders it almost indispensably requisite that the 
female, unaccountably neglected by Wilson, as he 
generally granted this distinction in similar, and often 
in less important, cases, should be described in this 
work. Hardly any North American bird more abso- 
lutely stands in need of being thus illustrated than the 
beautiful finch which is now the subject of our con- 
sideration. It could scarcely be expected that the 
student should easily recognize the brilliant indigo bird 
of Wilson’s second volume in the description which is 
now given of it. But, however simple in its appearance, 
the plumage of the female is far more interesting and 
important than that of the male, as it belongs equally 
to the young, and to the adult male after the autumnal 
moult, and previous to the change which ensues in the 
spring, — a large proportion of the life of the bird. 
The importance of a knowledge of these changes 
will also be duly estimated on recurring to the copious 
synonymy, by which it will be seen that several nominal 
species have been made by naturalists who chanced to 
describe this bird during its transitions from one state 
to another. Errors of this kind too frequently disfigure 
the fair pages of zoology, owing to the ridiculous 
