143 
AZURK-CROWNHD HUMMING-BIRD. 
Trochilus quadricolor Vi eillot. 
Plate IX. 
Trochilus quadricolor, Vieillot.- — Oiscau-mouchc a tetc dV.ur, 
Oraismya cyanoccphala, Lesson , Histoire Naturclle ties 
Oiseaux-mouches. Supplement , pis. xvii. and xviii. 
This very beautiful species has been described b s - 
Vieillot by the name ive have adopted, as that of its 
prior describer; and although perhaps not quite so 
applicable as that given by Lesson, it should be 
adopted. We are at a loss to understand why that 
ornithologist has introduced so many changes of no- 
menclature in his beautiful monograph. 
An inspection of the plate will show a difference 
of fonn from any of those previously described ; and 
it is probable that this species will form the type, or 
a very marked individual, in one of the subdivisions. 
The total length is nearly four inches ; the bill is 
straight, rather enlarged at the base, and of a clear 
yellow, except the tip, which is black ; the tarsi 
are very short ; a patch, or cowl, of brilliant blue, 
covers the crown, extending to the occiput, from the 
