38 NATURAL HISTORY OF BIRDS. 



their African relatives. The marks which they have in common with them, and which 

 consequently distinguishes both these from the cassowaries and emus, besides those 

 which separate the two inter se, have been pointed out briefly under the head of the 

 foregoing super-family, with the exception that in the Kheida3 the pubes are free, while 

 the ischia are united in a ventral symphysis, that the maxillo-palatines do not touch 

 the vomer, and that only a left carotid is present. We shall therefore here only men- 

 tion a feature shared by no other member of the order, viz., the peculiar and highly 

 specialized lower larynx. This was first discovered by the French naturalist, Mr. Alix, 

 in 1874, and afterwards fully described by the late Professor Forbes, who sums up its 

 most striking characters as follows : " In the possession of a tracheal box formed by 

 the fusion of the few last tracheal rings, in the greater amount of specialization of 

 the first two bronchial semi-rings of each side, in the presence of district interamular 

 membrane-covered fenestraa, in the development of a well-marked cartilaginous pes- 

 sulus, and in the possession of a pair of true intrinsic syringeal muscles running from 

 the trachea to the bronchial semi-rings, Rhea stands out by itself as sharply opposed to 

 all the remaining ' Ratite ' birds." 



Three species, all from South America, are known at present ; the old and rather 

 well known " Avestruz " of the Gauchos, and a nearly ally, described about fifteen years 

 ago by Dr. Sclater, both referable to the restricted genus Rhea, and named respectively 

 Rhea rhea (or Mh. americana) and JRh. macrorhyncha. The latter, the true habitat 

 of which still seems to be doubtful, is considerably smaller, as it stands six inches lower 

 than the female of the common nandu, but has a much longer bill, and is, besides, 

 much darker, the top of the head and streaks at the back of the neck in particular 

 being deep black. Both these are distinguished from Rh. darwinii in having scutel- 

 late tarsi, which in the latter are reticulate. It has therefore been made a separate 

 genus, Pterocnemia, a further character of which, in addition to several anatomical 

 differences, is that the leg is plumed below the knee for several inches. The termi- 

 nal white band on the wing feathers is a striking color mark. 



Not only is the nandu the oldest known species, but also the one having the 

 greatest distribution, occurring as it does, from southern Brazil to Magellan's Strait. 

 The general color is a brownish gray, lighter, nearly whitish on the belly ; the small 

 and narrow feathers on the crown, nape, and upper neck, are blackish in the male, 

 lighter in the female, which is the smaller of the two, the former measuring about six 

 feet in length, the latter hardly five and a half. 



Living on the pampas, and feeding on grasses and seeds of different herbs, and also 

 on the red berries of the Empetrum rubrum, the Rliea, like its African cousin, has 

 chiefly to rely upon its legs and acute sight for escaping danger, but seems to have devel- 

 oped considerably more intelligence, though he has often to pay the penalty of a too 

 great curiosity with his life ; and Darwin relates how, though fleet in its paces, and 

 shy in its nature, it yet falls an easy prey to the hunters, who confound it by approach- 

 ing on horseback in a semicii-cle. He also states that when pursued it generally 

 prefers running against the wind, expanding its wing to the full extent. Mr. Barrows 

 has recently in "The Auk" given some intei-esting information as to the manner in 

 which the 'Avestruz' is hunted in Lower Uruguay, as follows: "During our stay at 

 Puan, about two hundred Indians united in a two-days' ostrich-hunt, resulting in the 

 capture of about sixty birds of all sizes, from the full grown adult down to two-month 

 ' chicks.' They begin by beating over a lai-ge tract of the plain, and then closing in 

 around the game started. Stout greyhounds are used to good purpose, usually pulling 



