148 



THE VERTEBRATE SKELETON. 



The four bones of the distal row are respectively car- 

 palia 2, 3, 4 and 5. 



The hand consists of four digits, that corresponding to 

 the thumb of the human hand, judging from the analogy of 

 the frog probably being the one that is absent. 



Each digit consists of a somewhat elongated metacarpal 

 and of two or three phalanges. The metacarpals are contracted 

 in the middle and expanded at either end. They are connected 

 with the carpus by cartilage, and the articulations between the 

 several phalanges, and between the metacarpals and phalanges 

 are also cartilaginous. The second, third, and fifth digits 

 have two phalanges apiece, the fourth, which is the longest, 



18- 



m 



FlG. 23. A RIGHT POSTERIOR, AND B RIGHT ANTERIOR LIMB OF A NEWT 



x 1 (Molge cristata). 



10. humerus. 



11. radius. 



12. ulna. 



13. radiale. 



14. intermedium and ulnare fused. 



15. centrale of carpus, the pointing 



femur. 



tibia. 



fibula. 



tibiale. 



intermedium. 



fibulare. 



centrale of tarsus. 



tarsale 1. 



tarsalia 4 and 5 fused. 



I. II. III. IV. V. digits. 



line passes across carpale 2. 



16. carpale 3. 



17. carpale 5. 



