Genus — I D G E N I A . 
ViDGBNiA, nov. Type F. castaneiventris (Gould). 
I SEPARATE this species on account of the difference in the plumage stages, 
the immature of this genus having the plumage almost as in the adult, whereas 
in Gacomantis the immature feathering is so different, being conspicuously 
barred above and below, as to have caused many times the separation of 
new “species.” 
When this suggested itself, I examined the birds and then found, as might 
have been expected, that small structural differences were apparent. Thus, 
the tail is longer than the wing, which has developed a different wing-formula, 
the tip being formed of four feathers, the second, third, fourth and fifth, the 
third and fourth being subequal, the second and fifth being also equal. 
