1878.] 



MR. D. G. ELLIOT ON THE GENUS PTILOPUS. 



of generic value ; and it is only when a great series has been obtained 

 that it is perceived how these gradually disappear or become evolved 

 into something quite different. It is from the lack of material to 

 show this fact that such a genus (among others) as Chrysxna has 

 been accepted for Pt. victor and Pt. luteovirens. First established for 

 the latter species, chiefly on account of the lanceolate form of the 

 feathers, it was quickly perceived, on the discovery of Pt. victor, 

 that the genus could not rest on this character ; for the two species 



Fie 4. 



Ptilopus geelwnckianus. Mafor. 

 First primary normal in shape ; tarsus completely feathered. 



Ptilopus coronulatus. Aru. 

 First primary abruptly attenuated ; tarsus completely feathered. 



were generically essentially the same, and yet Pt. victor did not 

 possess lanceolate feathers. The partly covered tarsus is not suffi- 

 cient to separate them from Ptilopus ; for, as I have shown, many 

 species of that genus have also the tarsus half nude. The normal 

 shape of the first primary also fails, as this is also possessed by other 

 species of Ptilopus ; and therefore no characters remain worthy of 

 separating these birds generically from the other members of the 

 group, those that exist being only of specific value. Bonaparte has 

 proposed most of the generic divisions ; and he founded them mainly 

 upon the colour of plumage, sometimes placing the two sexes, or 

 adult and young, of the same species in different genera (vide Pt. 

 superbus, Pt. luteovirens, &c). I have not been able to discover 



