394 BIRDS. 



legs are extremely robust and powerful, and the hind-toe is 

 entirely wanting, except in the Aptcryx, in which it is rudimen- 

 tary. The anterior toes are two or three in number, and are 

 provided with strong blunt claws or nails. The plumage pre- 

 sents the remarkable peculiarity that the barbs of the feathers, 

 instead of being connected to one another by hooked barbules, 

 as is usually the case, are remote and disconnected from one 

 another, presenting some resemblance to hairs. 



The living Cursorial Birds are the Ostrich (Struthio camelus\ 

 the American Ostriches (Rhea), the Emeu (Dromaius), the 

 various species of Cassowary (Casuarius), and the Aptcryx 

 (fig. 332). Of the extinct forms of the Cursores, the most ancient 

 appears to be the Gastornis Parisiensis of the Eocene Tertiary. 

 This bird seems to have attained the size of an Ostrich, and it 

 appears to have points of affinity with the Natatorial and Gral- 

 latorial Birds. In the superficial deposits of New Zealand have 

 been found, as already mentioned, the remains of several species 

 of Dinornis and Palapteryx, along with bones of the now ex- 

 isting Apteryx. In similar deposits in Madagascar occur the 

 bones of the gigantic sEpiornis ; and in the bone-caves of 

 Brazil have been found remains of the American Ostriches 

 or Rheas. 



ORDER IV. RASORES. The fourth order of Birds is that of 

 the Rasores, or Scratchers, often spoken of collectively as the 

 " Gallinaceous" Birds, from the old name of "Gallinae," given 

 to the order by Linnaeus. The Rasores are characterised by 

 the convex, vaulted upper mandible, having the nostrils pierced 

 in a membranous space at its base. The nostrils are covered 

 by a cartilaginous scale. The legs are strong and robust, 

 mostly covered with feathers as far as the joint between the 

 tibia and tarso-metatarsus. There are four toes, three in front 

 and one behind, the latter being short, and placed generally at 

 a higher level than the other toes. All the toes terminate in 

 strong blunt claws suitable for scratching (Gattinaca), or in 

 more slender claws adapted for perching (Columbacd). The 

 order Rasores comprises the various species of Grouse (Tctra- 

 onida], the Partridges, Francolins, and Quails (PerdicidcE), the 

 Turkeys, Fowls, Pheasants, and Pea-fowl (Phasianida), the 

 Pigeons and Doves (Colnmbid<z\ and the recently extinct Dodo 

 (Didus inept us). 



The earliest remains of the Rasorial Birds appear in the 

 Eocene Tertiary, where traces of a Partridge have been found. 

 In Post-Tertiary deposits occur the remains of birds more or 

 less closely allied to the existing Pigeons, Grouse, Quail, 

 Pheasant, Fowl, and Tinamou. 



