650 



DR. P. CHALMERS MITCHELL OX THE 



between the sharp unbroken edge and a fully formed comb can 

 be found in nearly allied birds, and it must be a matter of 

 individual taste at what particular stage of elaboration it is 

 possible to describe the serration as a comb. It is at least certain 

 that Balceniceps cannot be separated from Scopus and the Herons 

 and associated with the Storks because of absence of pectination. 



Text-fi<r. 120. 



Modified Claw in some birds. 



Claw of 1 he third toe of the right foot, in each case the left-hand figtire showing the 

 dorsal aspect, the right-hand figure the axial side. 



1. Red-billed White Ibis (Eudociinus longirostris). 



2. Shoe-bill {Balasniceps rex). 



3. Tufted Unibre (Scopus umhretta). 



4. South American Little Bittern (Butorides cyanurus). 



5. Nacunda Goatsucker {Podargus nacunda). 



It seems obvious, however, that the forma,tion of a comb falls 

 in the category of what I have termed " muitiradial apocentri- 

 cities," modifications from the normal or primitive type, which 

 as they have occurred repeatedly and independently, afford no 

 information as to the systematic position of the animals in which, 

 they occur. By the kindness of Mr. Seth-Smith I have looked 

 through a number of the skins in the collection of the Society, 

 and with the assistance of Mr. Ogilvie-Gi'ant a still lareer number 



