8 BIRD GALLERY. 
the palatine, but forming a close union either by fusion or by over- 
lapping suture with the base of the vomer. 
The majority of the members of this group have become flightless, 
a fact which has brought about many modifications of the skeleton 
and feathers. The ‘linamous alone have retained the power of 
flight. 
Tie Ratite are divisible into seven Orders, probably derived from 
three distinct stocks. Hach Order can be readily defined, and presents 
one or more points which indicate extreme specialization. 
On account of the structure of the palate, the members of this section 
may be regarded as the most primitive of living birds. 
The seven Orders of the Ratitz are the following :— 
1. Struthioniformes . One genus, Struthio. 
2. Rheitormes ...... Two genera, Rhea and Pterocnemia. 
3. Dinornithiformes - 
eee Numerous genera. Extinct forms. 
4., ee 5 
5. Casuariiformes .... Two genera, Casuarius and Dromeus. 
6. Apterygiformes... One living genus, Apteryx, and two 
extinct genera. 
7. Tinamiformes ... Numerous genera. 
The characters by which the Orders are distinguished are fully 
explained in the table-case in the first bay. 
eres Order 1. STRUTHIONIFORMES. Osrricu-rerer. 
in Bay. }| 
Though closely allied to the Rheas, which they resemble in general 
appearance, the members of this order may be at once distinguished 
from all others by possessing only dwo toes. Of these the one corre- 
sponding to the middle of the three anterior toes in ordinary birds (the 
third of the complete set) is much the largest and supports the greater 
part of the weight. It bears a stout pointed nail. The smaller outer 
(or fourth) toe often wants the nail. The whole of the head and neck 
as well as the legs are bare, or only covered with short down. The body- 
feathers are single, having no aftershaft, aud the feathers of the wings 
and tail (corresponding to the ‘remiges’” and ‘ rectrices” 
birds) are of considerable size, but soft and plumose. 
of ordinary 
Family StrurHionip&., OstRicuEs. 
The Ostriches, the largest of living birds, are represented by the 
single genus Struthio, which contains at least four living species 
