134 HIGH SCHOOL ZOOLOGY. 



lias the cliaractor of contour or qiiill-foathors, tho plumes of 

 tlio ostrich being nothing but gigantic downs. Instead of the 

 boues of the head uniting early with each other, the sutures arc 

 quite evident, and the cervical ribs are for a long time movable, 

 instead of being coalesced with the vertebraj. Again, either 

 the ]iubic or iscliiac bones or both may form a symj^hysis as they 

 do in most living reptiles ; and, at least, there is a greater re- 

 semblance to the Dinosaur pelvis than thei-e is in tho carinate 

 birds. Other anatomical features of the Ratita3 are adaptive ; 

 the functionless nature of the fore-limbs is associated with the 

 reduction in size of their bones and of the clavicles, while the 

 adaptation of the hind limbs to rapid locomotion leads to a loss 

 of one or two of the four toes. ' 



There is great structural diffei-ence between the families of Ratit.'B, and 

 they are also marked oft geographically from each other. New Zealand 

 has the Kiwis {Aptcrij.c), small forms of about the size of a turkey with a 

 very rudimentary anterior extremity and four toes, of which the hinder 

 one is strongly clawed. Allied to it are the remains of various giant birds 

 (Dinornithkkt), recently extinct and found for the most part in New Zea- 

 land (Fig. 95). These Moas, as they are named by the Maoris, stood ten 

 feet from the ground, and their eggs were of very lai-ge size. Allied to 

 them is a similar form from Madagascar [jEitijorim), believed to be the Roc 

 of Eastern Fables ; the skeleton of this genus is not well known, but eggs 

 have been found of enormous size, which hold as much as two-and-a-half 

 gallons, and have been estin^ated to be equivalent in contents to twelve 

 dozen hen's eggs. In the I'est of the Australian region two other genera, 

 the Cassowaries (Casuariua), and the Emus {Droiiianui), are found, while 

 in South America, are the three-toed Ostriches (Rhea), and _ in the 

 deserts of Africa and Western Asia, the two-toed Ostrich (Struthio 

 camelus). 



Like the Carinataa the Ratita} have no teeth in the jaws, which are 

 simply clothed with a horny beak, but the genus Hcsperornis, which as 

 far as its sternum is concerned is one of the Ratitae, had only a horny 

 beak on its premaxilla^, while the maxilhe and the mandibles had teeth 

 fixed in a continuous groove. Besides the teeth, there were numerous 

 other characters which give it an intermediate position between the 

 Dinosaurs and the Ratitje. The anterior extremity is represented by the 



