48 
Cnemiornis, although also with a “ ratite” or uncarinate sternum, must stand beside 
Cereopsis in the Anserine group of Anatide. 
The Didines are but generic modifications of a great natural division of Rasores, the 
existing members of which, of smaller size, retain their faculty of flight. 
Dinornis shows the consequence of disuse of wings in a greater degree than does 
Apteryx. But, although the winged forms from which the Kiwi, the Cassowary, the 
Emu, the Rhea, the Ostrich, and the 4pyornis have severally degenerated remain to 
be determined, the wingless kinds each have structural characteristics encouraging the 
quest, and testifying against the artificial group (Megistanes, Vieillot ; Proceri, Iliger ; 
Ratite, Merrem; Struthionide, Vigors) based upon modifications of the breast-bone 
and scapular arch, the consequences of disuse and degeneration of the muscles of flight, 
and with which a loose character of plumage is more or less associated. 
The results of the researches which have determined the real affinities of extinct birds 
with keelless breast-bones and long-angled scapulo-coracoids, devoid of acromial and 
clavicular processes, support a reasonable expectation that the existing wingless genera, 
which have been shown to differ from one another considerably in important anatomical 
structures, in correlation with their distinct and remote habitats, will be ultimately 
referred to as many distinct natural groups which are now, or which formerly have 
been, represented by volant and typical members of the feathered class. 
EXPLANATION OF THE PLATES. 
PLATE IV. 
Fig. 1. Reduced side view of the skeleton of the male Solitaire. 
Fig. 2. Reduced side view of the skeleton of the female Solitaire. 
Fig. 3. Copy of a figure of the living Solitaire, from the frontispiece to Leguat’s work, 
above cited. 
PLATE V. 
Fig. 1. Side view of the skull of the male Solitaire. 
Fig. 2. Top view of the skull of the same. 
Fig. 3. Occipital surface of the skull of the same. 
Fig. 4. Top view of the skull of the female Solitaire. 
Fig. 5. Under view of the skull of the same. 
All the figures are of the natural size. 
