188 ELEMENTS OF ORNITHOLOGY. 
much longer, and segmented, pair are attached, one on either 
side, to the hinder part of the basi-hyal, and these are called the 
“oreater horns,” greater cornua, or thyro-hyals. It is these 
which are so prolonged and so singularly fixed in the Wood- 
peckers, where they serve as a spring to help the darting for- 
wards of a spear-like tongue borne at the end of a long and 
slender basi-hyal. 
Tre Limes. 
The Appendicular Skeleton.—This, as before said *, consists of 
two limb-girdles, each supporting a pair of limbs—one thoracic, 
theskeleton of the shoulder or shoulder-girdle, the other pelvic, 
the skeleton of the hip. 
The thoracic limb-girdle—which is also called the scapular 
arch—is firmly attached, as before said, to the ventral por- 
tion of the thoracie part of the axial skeleton, namely, to 
the anterior end of the sternum, where it is fixed into the 
grooves there situate. It has no other connection with 
the axial skeleton. The girdle consists of three parts or 
elements on either side, and the bone of the upper arm—the 
proximal bony segment of the limbs—is articulated to two of 
these three elements at the point where they meet. These 
three elements are termed respectively the coracoid, the clavicle, 
and the scapula, 
The girdle is actually completed below by the junction of 
the two lateral portions of the clavicle. 
The Coracoid.—This is a bone which is not only invariably 
present, but is the strongest and most important one of the 
thoracic limb-girdle. It is that bone which at one end is 
fitted into the groove of the sternum, while at the other it is the 
main support of the bones of the wing. Its size is directly 
related to the use of the wing, and is immense in the Penguin, 
which has to exert so much force with its wings, and which 
employs the motions of flight in the denser medium of water, 
as this bird may be said to fly submerged. It is a straight, 
stout bone, more or less expanded below for its implantation 
in the sternum, and bifurcating at its upper end into two pro- 
cesses which unite with the other elements of the ‘“ scapular 
arch.” One of these, that which joins the scapula, presents at 
* See ante, p. 168, 
