THE SKELETON 39 



six bones, the proximal ulnare, centrale and radiale, 

 and the distal carpales. 



241. The distal group of bones is the manus or liand, 

 containing the five metacarpales and the phalanges, 

 two for each of the inner digits, three for the outer 

 digits, fifteen bones in all. 



Examine the pelvic appendage (pelvis and leg) and identify 

 the following bones: 



The girdle consists of: 



242. the long, sword-shaped ilium, articulating at its 

 cephalic end with the ninth vertebra, 



243. the ischium, caudal to the illium, and 



244. the pubis, ventral to the two others. The acetabu- 

 lum, or cup into which fits the head of the femur 

 (245), is formed by the union of these three bones. 



The free appendage contains twenty-eight bones. 



245. The proximal bone is the femur, its head fitting into 

 the acetabulum. 



246. Distal to this is the tibio-fibula, resulting from the 

 fusion of the embryonic tibia and fibula. 



247. This is followed by the tarsus or ankle containing 

 five bones, the tibiale, fibulare, centrale (at the 

 base of the prehallux (10), and two tarsales. 



248. The distal group of bones is the pes or foot, contain- 

 ing two small bones of the prehallux,^ five meta- 

 tarsales, and the phalanges, two in the first and 

 second digits, three in the third and fourth digits, 

 and four in the fourth digit, twenty-one bones in all. 



* The prehallux may have from one to three elements. 



