1865.] MR. W. S. DALLAS ON THE FEATHERS OF DINORNIS. 267 
horn-colour above, probably from exposure to external influences. 
The accessory shaft is of a pale horn-colour, and appears to be nearly 
cylindrical. 
Fig. 1. The basal portion of a feather detached from the skin, of the natural size : 
a. The accessory shaft. 
2. Part of a barb with the barbules ; magnified 15 diameters. 
3. Apical portion of a barbule ; magnified 150 diameters. 
The structure of the web is somewhat different from that which 
occurs in the Emu and the Cassowary. Towards the base of the 
shaft the barbs spring in groups of four or five together from nearly 
the same spot, and thus this part of the web assumes a tufted aspect. 
As we advance towards the apex this arrangement speedily ceases ; 
the number of barbs springing from the shaft gradually diminishes, 
until each side bears only a single series of these appendages. The 
barbs consist of slender, flattened fibres, bearing long, silky, and very 
delicate barbules, without any trace of barbicels, but presenting a di- 
stinctly beaded appearance when examined by a simple lens. Under 
