CLASSIFICATION OF BIRDS. 619 



they are sometimes left during part of the day simply covered by the 

 sand. 



The American Ostrich (Rhed] is represented by three species in the 

 S. American Pampas. In the Rhea there are three toes, all clawed, 

 and the ischia form a ventral symphysis. There are no clavicles. Only 

 here among Ratitae is there a well-developed syrinx. -The caeca are 

 large. The male excavates a shallow nest in the ground, and there, 

 surrounded by a few leaves and grasses, the numerous eggs are usually 

 laid. It seems that the male bird alone hatches the eggs. Single eggs 

 are often laid here and there on the plains, but these are not incubated. 



The Emu (Dromtzus] is represented by two species in Australian 

 deserts and plains. The fore limb is greatly reduced, the feathers have 

 long aftershafts. Nearly related are the Cassowaries ( Casuarius] living 

 in the Austral- Malayan region, eight species in the Papuan Islands, one 

 in N. E. Australia, and one in Ceram. They live in the forests and 

 scrub. The fore limb is very small, with the shafts of the wing feathers 

 reduced to spines ; the ordinary feathers having long aftershafts. On 

 the top of the skull there is a horny helmet, covering a core of light 

 spongy bone ; this protects the bent head as the bird rushes through the 

 scrub. There are three toes, the inner one with a long sharp claw a 

 formidable weapon. In both these genera the clavicles are rudimentary 

 and the caeca small. 



The Kiwi (Apteryx] forms a very distinct genus of Ratitae, represented 

 by four species, restricted to New Zealand. It is not larger than a 

 hen, and has simple hair-like or bristle-like feathers, a long bill and 

 terminal nostrils, a very rudimentary wing and no clavicles, and no 

 distinct tail feathers. There are four clawed toes. The caeca are large, 

 It is a nocturnal bird, swift and noiseless in its movements, feeding in 

 great part on earthworms. The egg is very large for the size of the 

 bird. 



Among the extinct forms are the gigantic Moas (Dinornis], which 

 seem to have been exterminated in New Zealand in comparatively 

 recent times. The fore limbs were almost completely reduced, the 

 hind legs were very large, and some forms attained a height of ten feet 

 or even more. 



Another recently lost order of giant birds is represented by remains of 

 ^Epyornis found in Madagascar. Some of these indicate birds as large 

 as ostriches, but eggs have been found holding six times as much as that 

 of an ostrich. 



Besides these there are other extinct Ratitae (Stereornithes) such 

 as BrontomiS) Dasornis, and Gastornis. 



We may think of the Ratitae, according to W. K. Parker, as " over- 



frown, degenerate birds that were once on the right road for becoming 

 ying fowl, but through greediness and idleness never reached the 

 ' goal,' went back, indeed, and lost their sternal keel, and almost lost 

 their unexercised wings," 



2. Division ODONTOLC/E. Extinct toothed birds from N. American 

 Cretaceous strata, e.g., Hesperornis, somewhat like a swimming 

 ostrich, with sharp teeth sunk in a groove, with vertebrae like those 

 of modern birds. 



