228 GALLINA, GALLINACEOUS BIRDS. 
Subclass II, AVES TERRESTRES, or CURSORES, 
TERRESTRIAL BIRDS. 
This second series includes all living birds, between the Columbe and the Lam- 
ellirostres, excepting, probably, the ostriches and their allies. Like the other two 
divisions called ‘‘subclasses” in the present work, it is insusceptible of definition 
by characters of more than the slightest morphological importance, and conse- 
quently has nothing of the taxonomic value commonly attaching to groups so 
named. It may be considered, however, to represent the teleological generalization, 
that a certain number of birds, differing greatly in structure, are collectively 
modified in a way that fits them for similar modes of life—that several different 
types of structure are bent to subserve a particular end. In a certain sense, there- 
fore the Cursores may be said to hold together more by analogical relationship 
than by special morphological affinity ; and among them there is certainly greater 
diversity of structure than that existing between some of them and the birds 
standing upon the confines of IJnsessores and Natatores. On the one hand, the 
gallinaceous birds shade directly into the columbine, while on the other, the 
Grallatores are perfectly linked with the Natatores by means of the flamingoes. 
As implied in their name, the birds of this series are especially terrestrial in habit, 
spending most of the time on the ground, not on trees or the water; although most 
of them fly vigorously, and some swim well. A character of general applicability . 
is the combination of long or strong legs (as compared with Jnsessores), with the 
freedom of the knee and lower thigh from the body (as compared with Natatores). 
The hallux as a rule is reduced in length and elevated in position, and is often 
absent altogether—a modification rarely found outside this group; the front toes 
are generally webbed at base, often cleft, occasionally lobed or even full-webbed. 
Excluding the struthious birds, which cannot well be brought into this connection, 
the series represents two commonly received orders. 
Order GALLINA. Gallinaceous Birds. 
Equivalent to the old order Rasores, exclusive of the pigeons— this name being 
derived from the characteristic habit of scratching the ground in search of food ; 
connecting the lower terrestrial pigeons with the higher members of the great 
plover-snipe group. On the one hand, it shades into the Columbe so perfectly that 
Huxley has proposed to call the two together the ‘‘ Gallo-columbine series ;” on 
the other hand, some of its genera show a strong plover-ward tendency, and have 
even been placed in Limicole. The birds of this family are more or less perfectly 
