Genus — LEWI NORN IS . 
Lewinornis Mathews, Austral Av. Rec., Vol. II., 
pt. 2/3, p. 57, Oct. 23, 1913. Type (by original 
designation) ... ... ... ... ... Sylvia rufiventris Latham. 
I differentiated this genus thus : “ Differs from Pachycephala Vigors and 
Horsfield, in its weaker bill, shorter wing and tail, and weaker feet.” 
Though the male of this genus shows a similar colour pattern to that of 
the preceding it cannot be classed with it. When I wrote my note on colour 
pattern, which was published in the Emu, the editors commented on why I 
differentiated this generically while admitting a similar colour pattern. This 
comment was due to a misunderstanding, as though genera may be grouped by 
means of colour pattern, distinct genera may have been evolved even though 
the colour pattern be retained. In the present case the plumage changes are 
quite different, as the genus appears to have originated by a different route 
from Pachycephala. In that genus the young are unicolour red in the nest, 
but as they lose this plumage the young rarely show obscure streaking on the 
breast, which soon disappears and then they rapidly diverge from the original 
style until the black and yellow stage is reached. 
In the present case the young are striped and the grey and rufous colora- 
tion is directly achieved and the form is apparently confined to Australia, 
though not present in Tasmania. The elimination of the stages seen in the 
preceding genus and the acquisition of a distinct style of coloration is quite 
worthy of generic rank as we have been able to trace many stages in 
Pachycephala s. sir. with the retention of the yellow and black plumage. At 
present I am considering the evolution of all these Pachycephaloid genera 
from the same source as Colluricincla and will deal with that idea later on. 
