RANA, 351 
bears a small cartilaginous 74. The eighth is like the 
preceding in general structure but is amphicalous, t.e., it has 
a concave articular surface ateach end. The xnth vertebra 
has large transverse processes to which is attached the pelvis. 
Hence this vertebra is called the sacrum. It is biconvex, 
with a convexity at each end of the centrum. The uvostyle 
is a long bone formed of at least three fused vertebrae. It is 
hollow for part of its length and contains the posterior end 
of the spinal cord. 
Fig. 248.—PrecroraL GIRDLE oF Rana. 
Episternum. 
Clavicle. Suprascapula. 
Omosternum. 
Coracoid. 
Sternum. 
Xiphisternum. 
View with dorsal parts bent downwards. Bone is black and cartilage dotted. 
The presence of this urostyle, the single sacral vertebra 
and the small number of vertebre are the important 
peculiarities of the vertebral column. The vestigial ribs 
are also to be noted. 
Fig. 249.—FORE-LIMB OF Rana. 
Phalanges of 
Digits. 
Metacarpals. 
Note fusion of radius and ulna and absence of pollex, a metacarpal only remaining. 
The peripheral (or appendicular) skeleton consists of 
the two limb-girdles and limbs. These are constructed on 
the pentadactyle type (see page 420). The shoulder-girdle 
(pectoral girdle) consists of paired clavicles and coracoids 
