Genus — B ELCHERA. 
Belchera Mathews, Austral Av. Rec., Vol. I., pt. 5, p. 109, 
Dec. 24th, 1912. Type (by original designation) : Petroica rosea Gould. 
From the preceding genus I differentiated this genus as “ Differs from 
Erythrodryas in its shorter, broader bill, with weaker legs and feet; the 
wing has the fourth primary longest and the first primary proportionately 
shorter than in the genus named, which has also the fifth primary longest. 
The tail is almost square.” 
Similar in coloration to the preceding. The rictal bristles, which are strong 
in that, are weak in this. 
The wing-formula also slightly differs, as the thud primary is longer than 
the sixth, the second equal to the seventh and the first less than half the 
length of the second. 
As these species represent each other, they probably indicate stages in 
evolution through difference in habits and the resemblance in coloration is 
worthy of consideration. Whether this has developed more quickly owing to 
greater stresses on the mainland, or the island form has become more differen- 
tiated owing to isolation, cannot be decided until the osteology of these Robins 
as a whole has been thoroughly studied and the important features recognised. 
Certainly this grey-backed series is connected by the Flame-breasted Robin 
with the Red-breasted black-backed birds, but the two Red-breasted black- 
backed forms differ more widely from each other than either does from one of 
the others. In connection with extra-limital species much recalling these 
similar colorations is found and comparative series can even be observe^, but 
the comparison between the Australian forms, as to their osteology, should 
be carried out by itself first and then examined in connection with the above 
indicated extra-limital species. 
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