FOSSIL BIRDS. 
361 
forms the sail. But the structure of the bird's wing is altogether 
different. The humerus bends back from the scapula (Fig. 6), the 
ulna and radius form the remige of the wing to which the quill - 
feathers are attached ; while the carpals and metacarpals of the 
second and third digits form the pinion, and the carpals and meta- 
carpals of the fourth digit are anchylosed together and form a 
little undeveloped finger of bone at the joint of the wing between 
the remige and the pinion. In the wing of the Pterodactyle (Fig. 
7) the little finger is made to do duty as the yard to spread the 
sail of leathern skin, while the rest of the fingers provided with 
strong hooked claws extend beyond the wing-joint as clutches 
for the monster to hang on by, as bats and vampires do, to 
points of rock or boughs of trees. 
The wing of the Archaeopteryx has one or two claws (Fig. 15), 
or rather hooks, but so have recent birds. The Pa/rra jacana, 
the Palamedea, the “ spur-winged goose," the Syrian black- 
bird, are all examples. These claws — and in the Archaeopteryx 
there might be, Professor Owen thinks, possibly three — are par- 
ticular developments of those digits which ordi- 
narily in birds are modified and disposed to form 
the pinion of the wing, and are not to be neces- 
sarily considered as in any way equivalent to the 
wing-finger of the Pterodactyles. They may have 
been used as hooks, but that they were so is 
not certain ; and in the spur- winged birds the 
spurs are generally pointed, and usable apparently 
only as weapons of offence or defence. (See the 
Chaja Screamer, Plate XVI., fig. 10.) The reason, 
it is said, that “ possibly the Archaeopteryx had these two or 
three wing-hooks, is that these bones are displaced in the slab, 
and therefore may have been washed together. There is reason, 
however, to think that other osseous remains lying near to 
the hooks may be carpal bones. 
The form of the foot in the Archaeopteryx is also decidedly 
that of a bird (Fig. 11). Its specialities may perhaps be best seen 
by a comparison with that of the Falcon (Fig. 13), or some other 
strong-footed, retractile-clawed, raptorial bird, between which 
class and the Perchers, the Archaeopteryx will probably take 
zoological rank. In the Geologist for January last I pointed 
out the particular organs indicated by a cast of the brain-cavity 
of the skull, which has been remarkably preserved in the stone ; 
and I would here draw attention to another portion of this 
wonderful fossil, which has hitherto received no published notice. 
While the Archaeopteryx slab presents us with the bones of 
the wing, the furculum, the ribs, the ischium, the numerous 
vertebrae of an extraordinary and long tail, into which the 
feathers were set in pairs, — while the imprints of these feathers 
