KATTT^. 255 



the Birds, with the principal fossil forms and geological 

 range of each, so far as known : — 



Subclass I. — Eatit^. 



Order Cursores. — The first order of Birds is that of the 

 Cursores, or Eunners, comprising the Ostriches, Eheas, Cas- 

 sowaries, Emeus, and the singular Apteryx of New Zealand, 

 The Cursores are characterised by the rudimentary condition 

 of the wings, tvhich are so short as to he useless for flight, and 

 hy the compensating length and strength of the legs. In ac- 

 cordance with this condition of the limbs, many of the bones 

 retain their marrow, and the stermcm (fig. 583) is destitute of 

 the prominent ridge or heel, to which the great pectoral muscles 

 are attached (hence the name of Batitce, applied by Huxley 

 to the order). In the Ostrich, the pubic bones of the pelvis 

 unite to form a symphysis pubis, as they do in no other 

 bird ; and in all, the pelvic arch possesses unusual strength 

 and stability. The legs are extremely rohust and povjerful, 

 and the hind-toe is entirely ivanting, except in the AjJteryx, in 

 which it is rudimentary. The anterior toes are two or three 

 in number, and are provided with strong blunt claws or 

 nails. The plumage presents the remarkahle peculiarity that 

 the larhs of the feathers, instead of being connected to one cm- 

 other hy hooked harhides, as is usually the case, are remote and 

 disconnected from one another, presenting some resemhlance to 

 hairs. 



The order Cursores may be divided into the two families 

 of the Struthionidce and the Ap>terygidce — the former charac- 

 terised by the absence of the hallux, and comprising the 

 Ostrich, Ehea, Emeu, and Cassowary, with several extinct 

 forms; the latter comprising only the Aptcryx (fig. 586) of 

 New Zealand, and characterised by the possession of a 

 rudimentary hallux. 



As regards the distribution of the Cursores in space, the 

 living forms are restricted to regions which lie, wholly or in 

 great part, to the south of the equator. Thus, the true 

 Ostriches (Struthio) are African ; the Eheas are South 

 American ; the Emeus are Australian ; the Cassowaries 



