770 . PHYLUM CHORDATA : CLASS AVES — BIRDS 



n. Sub-Class Neornithes 



The metacarpals are fused. The second finger is the longest, and 

 the third is reduced. If claws are developed at all, they are usually 

 confined to the thumb, but the first finger is also strongly clawed in 

 the ostrich and in the young hoatzin. Caudal vertebra are not more 

 than thirteen in number. 



I. Division Ratit/e. Running Birds with raft -like unkeeled 



breast -bone 



The African ostrich {Strutkio) is represented by two or three species, 

 at home in the plains and deserts of Africa, and notable for their size, 

 swiftness of foot, and beauty. There are but two toes, the third and 

 the fourth, with stunted nails. There are no clavicles. The pubes 

 form a ventral symphysis. The enormous size of rectum and caeca is a 

 unique character. The ostrich is polygamous, and at the breeding 

 season the hens lay the eggs, at intervals, in a hollow dug out in the 

 sand by the male. The eggs are incubated by both parents, but 

 especially by the cock. 



The American ostrich (Rhea) 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 Ratify is there a well-developed syrinx. The casca 

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

 there, surrounded b}'^ 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 

 come to nothing. 



The Emu {DromcBus) 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 ; tlie ordinary feathers have 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 Emu and Cassowary the clavicles are 

 represented by separate rudiments and the cajca are small. 



The Kiwi {Apteryx) forms a very distinct genus of Ratita?, 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 cajca 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 Ratitic are the gigantic Moas (Dinornis), which 

 seem to have been exterminated in New Zealand in comparatively 



