538 ZOOLOGY, 
in the upper Cretaceous beds of this country. The remains 
of Ichthyornis indicate an aquatic bird about the size of a 
pigeon. The reptilian affinities are seen in the vertebrae, 
which, unlike those of all other birds, are biconcave, and in 
the long, slender jaws, with stout, conical teeth held in 
sockets, as in the crocodiles. On the other hand, the wings 
were well developed, and the legs were of the ordinary bird 
type, the metacarpal bones being co-ossified, while the ster- 
num was keeled. In asecond member of the group (Hes- 
perornis) the teeth were in grooves, the vertebre as in recent 
birds, the sternum without a keel, and the wings were rudi- 
mentary (Marsh). , 
Sub-class 3. Ratite.—This group, represented by the kiwi- 
kiwi, the moa, cassowary, and ostrich, is characterized by 
the smooth unkeeled sternum and the short tail ; the wings 
are rudimentary* andthe hind legs strong, these birds (except 
Apteryz) being runners, and either of large or, as in the ex- 
tinct forms, of colossal size. The bonesare tilled with marrow. 
The simplest form is the ‘‘ kiwi-kiwi,’’ or Apteryx of 
New Zealand (Fig. 461), of which there are three or four 
species. It is of the size of a hen, witha long slender beak, 
the nostrils situated at the end of the upper jaw, while the 
body is covered with long hairy feathers. The female lays 
only a single large egg, which weighs one quarter as much as 
the bird itself, in a hole in theground. It is a night bird, 
hiding by day under trees. 
The giant, ostrich-like, extinct. birds. of: New Zealand, 
called moa, and represented by several species, chiefly of 
the genera Dinornis and Palapteryx (Fig. 461), were sup- 
posed to have been contemporaries of the Maoris or natives 
of New Zealand. While a fourth toe (Aallux) is present in 
the Apteryzx, the moa-bird has only three toes. 
The largest of the moas, Dinornis giganteus of Owen, 
stood nearly three metres (9$ feet) in height, the tibia or 
shin-bone alone measuring nearly a metre (2 feet 10 inches) 
in length. These moa birds belong to three genera: Di- 
nornis with ten, Palapteryx with three, and Aptornis with 
a single species. 
Allied to the moa was a still larger bird, the Mpyornis 
* The moa had glenoid cavities, showing that it had wings (Forbes). 
