376 ZOOLOGY. 
and are reduced to cartilaginous pieces in sharks. The pelvic 
girdle, or pelvis, consists of three bones, 7.¢., one dorsal, the 
tlium, and two ventral, the anterior of which is called pubis, 
and the posterior ischium. 
The limbs each consist of a single long bone, succeeded by 
two long bones, followed by two transverse rows of short 
wrist or ankle bones, and five series of long finger or toe 
bones, called phalanges. For example, in the fore limb of 
most Vertebrates, as in the arm of man, to the shoulder gir- 
dle, z.e., at the point of junction of the three bones com- 
posing it, is articulated the humerus ; this is succeeded by 
Fia. 374, 
Fig 375, 
Fig. 374.—Sternum and shoulder girdle of Frog (Rana 
temporaria). p, body of the sternum; sc, scapula; sc’, 
supra-scapula ; co, coracoid bone, fused in the middle line 
with its fellow of the opposite side (8) ; of, clavicle ; e, epis- 
ternum. The extreme shaded double portion below pis the 
xiphisternum. The cartilaginous parts are shaded.—After 
Gegenbanr. 
Fig. 375.—Fore-leg of a seal. S, eel #,, humerus ; 
0 olecranon ‘or tip of elbow; 2, radius; U, ulna; Po, 
pollex, or thumb. i : 
Fig. 376.—Pelvis or pelvic bones on one side of a marsu- 
piai (Kangaroo). 62, ilium; a, situated on the pubic bone_ 
(pubis) indicates the acetabulum or concavity for the artic- 
ulation of the head of the femur; 68, iechium, consolidated with the pubis. The 
three bones thus consolidated form the os innominatum ; m, marsupial bones ar- 
ticulated to the pubic bones.—After Owen. : ‘ 
the wina and radius, the carpals, the metacarpals, and the fin- 
ger-bones or phalanges, the single row of phalanges forming 
a digit (finger or toe). To the point of union (acetabulum, 
Fig. 376, a).of the three pelvic bones is articulated the fe- 
mur, or thigh; this is succeeded by the fidia and fibula 
(shank-bones), the tarsal (ankle-bones) and metatarsal bones, 
and the phalanges or bones forming the digits (toes). 
Figs. 378-380 represent the simplest form of the posterior 
limbs in the higher Vertebrates, that of the bird showing an 
