EAST ZOOL. GAL.] NATURAL HISTORY. 
63 
The family of Falcons (. Falconidce, Cases 8—30) have 
their heads covered with feathers, and the eyebrows promi¬ 
nent, giving the eye the appearance of being set deep in the 
head, and imparting a character to these birds, very different 
from that of the Vultures. The Noble Falcons, the birds 
used in falconry, have a roundish nostril, with a tubercle in 
its centre. Most of them have a deep notch on each side of 
the apex of the beak. The Ignoble Falcons have simple 
nostrils; some, as the Hawks {Astur), have ovate rather 
longitudinal nostrils, whilst the Honey Buzzard ( Pernis ), 
Osprey ( Pandion ), and Kites (. Milvus ), have an oblique 
slit covered with a valve behind, and the Eagles ( Aquila) 
and Sea Eagles ( Haliaetus ) have oblong exposed nostrils 
placed perpendicularly across the front of the cere. Among 
the Hawks, the most remarkable bird is the Secretary, 
found at the Cape of Good Hope, called also the Serpent 
Eater, from its preying on those reptiles; the French 
have attempted to naturalize this bird in Martinique, in 
order to destroy the lance-headed serpent, which abounds 
in that island. The Hen Harrier ( Circus ) has some resem¬ 
blance to the Owls. All these birds vary greatly in the 
colour of their plumage before they arrive at the adult state. 
The Nocturnal Birds of Prey, or Owls, ( Strigidce , Cases 
33—35,) have a large head, and their eyes placed in front, 
and more or less surrounded with a circle of radiating fea¬ 
thers. Their plumage is very soft, their ears* large, and 
placed just at the back of the disk of feathers which sur¬ 
rounds their eyes, and this developement of the organs of 
hearing probably compensates for the imperfection of their 
sight, at least in full daylight. The Owls have been divided 
into many genera, as the Eagle Owls {Bubo), Short-horned 
Owls ( Otus ), the Earless Owls ( Stria:, Syrnium, and 
Noctua). The species of the last genus fly more by day 
than the rest of the Owls, and the disk of feathers round 
their eyes is not so distinctly marked as in the other genera. 
The Perching Birds (Passeres Case 36—83) are ge¬ 
nerally smaller than the Raptores, their bills are weaker, 
and their claws slender and acute; like them, they have 
the hind toes articulated on the same plane with the front 
ones, which enables them to grasp their perch with ease and 
security. They are separated into five divisions, accord¬ 
ing to "the form of the feet and bill, each division contain¬ 
ing several families and genera. 
