The postaxial bone, the =ulna= (fig. 77, C), has the proximal end much enlarged, forming the =olecranon= (fig. 77, 11), and tapers gradually to the distal end. Near its proximal end the ulna is marked by a deep =sigmoid notch=, which bears on its inner side a concave surface (fig. 77, 12) for articulation with the trochlea. The pointed proximal end of the sigmoid notch is called the =coronoid process=. Somewhat in front of and below the sigmoid notch is a smaller hollow (fig. 77, 13), with which the radius articulates. In the young animal the ends of both radius and ulna are seen to ossify from centres different from those forming the shafts. The epiphyses forming both ends of the radius, and the distal end of the ulna are large, while that at the proximal end of the ulna is small, and forms only the end of the olecranon. The =Manus= is divided into _a._ The =carpus= or =wrist=, formed of a group of small bones. _b._ The =hand=, which includes firstly some elongated bones, the =metacarpals=, forming what corresponds to the palm of the hand, and secondly the phalanges, which form the =fingers=. The =Carpus= or =wrist=. The carpus of the dog consists of seven small bones, arranged in a proximal row of three, and a distal row of four. It differs much from the simpler type met with in the newt. The largest bone of the proximal row is the =scapho-lunar= (fig. 80, 1), formed by the fused =scaphoid= (radiale), =lunar= (intermedium), and =centrale=; it has a large convex proximal surface for articulation with the radius, and articulates distally with the trapezium, trapezoid, and magnum, and internally with the cuneiform. The =cuneiform= (ulnare) (fig. 80, 2) has a posterior rounded surface articulating with the ulna; it articulates in front with the unciform, and internally with the =pisiform= (fig. 80, 7), which is a comparatively large sesamoid bone on the ulnar side of the carpus. Frequently also there is a small sesamoid bone on the radial side of the carpus. The =trapezium= (carpale 1), =trapezoid= (carpale 2), and =magnum= (carpale 3) (fig. 80, 5) are all small bones, and support respectively the first, second, and third metacarpals. The =unciform= (carpalia 4 and 5) (fig. 80, 6) is larger, and supports the fourth and fifth metacarpals. The hand has five =digits=, each consisting of an elongated =metacarpal=, followed by =phalanges=, the last of which, the =ungual phalanx=, is pointed and curved, and bears the claw. Each of the metacarpals is seen in the young animal to have its distal end formed by a prominent epiphysis, and each of the phalanges, except those bearing the claws, has a similar epiphysis at its proximal end.