126 
ON THE CLASSIFICATION OF BIRDS. 
come the wings of the latter: hearing in mind this 
analogy, we find that the lemurs (^LemiiridtE'), opposums 
(Didelphidce), and kangaroos (Marmpidee)* , are among 
the largest footed quadrupeds. While the water rails 
(RalKd^), the grcatfoots lCrncid<s)i, the honeysuckers 
{Meliphagida;), and the large-legged thrushes (Cra- 
teropina), among birds, have the largest feet, with the 
largest claws, in the circles which respectively contain 
them : they are all, in short, so many instances of the 
Rasorial type. Size and strength of foot must not, 
how'ever, be confounded with length, for those birds 
which have the longest, have generally the most slender 
legs ; the whole of the typical Gmllatores, or waders, 
butjmore especially the genera, Himimtopxts, Avosetla, 
Mycteria, and Tachydromus. The flamingos {Phani. 
cnpterns) among the Anatidm; the serpent-eater (Gypo- 
geranm), in the rapacious order, and the larks in the 
circle of the Fringillidfe, are analogous types, and show 
that unusual length and sJ-endevness of leg, where it 
exists, is generally prevalent in the Gmllatorial types. 
The shortest feet, as just remarked, are almost always 
found in the aquatic type, whether belonging to the 
class of (piadrupeds or to that of birds. The seals 
and walnises, thus representing the pelicans, ducks, 
awks, and divers, in the Natatorial order, and these 
find their representatives among the perching groups, 
in the night-jars(Cnprimj(l(/idrt'), swifts (ITirundinidee), 
flycatchers {Miiscicapida), short-legged thrushes ( Srn’. 
chypodinof), and numerous other groups. Moderate 
feet (tliat is, when the tarsus is only slightly longer tlian 
the hind toe) is the average structure in the rapacious 
and perching orders, but the claws of the former, like the 
feline order of quadrupeds, are retractile, while the 
latter agree witli the feet of the qmrinmmna in having 
superior powers of grasping, or of prehension. Thus we 
perceive that the relatim sise of the feet, throughout 
the class of birds, is regulated by fixed laws, and that 
* Sec Classification of Quadrupeds, pn 82 lOfi ooo 
+ This family includes .Uwa and ^legapodL 
