The =fore-arm= or =antibrachium= consists of two bones, the =radius= and =ulna=. These are of nearly equal length, and are separated from one another by a considerable space except at their terminations. The =radius= (fig. 57, 2), the pre-axial and smaller bone, is straight and fairly stout; its proximal end articulates with the humerus by a slightly cupped surface, while its distal end, which articulates with the carpus, is convex and somewhat expanded. The =ulna= (fig. 57, 3) is longer, stouter, and slightly curved. Its proximal end is expanded, forming two surfaces which articulate with the trochlea of the humerus; behind them it is drawn out into a short blunt =olecranon process=. Its distal end is less expanded, and articulates with the carpus and also with the radius. The =Manus=. This includes the carpus or wrist, and the hand. The =Carpus=. While in the embryo the carpus consists of five distinct elements arranged in a proximal row of two and a distal row of three, in the adult only the proximal bones can be clearly distinguished, the distal ones having become completely ankylosed with the metacarpals to form the =carpo-metacarpus=. The two distinct carpal bones are the radial carpal and the ulnar carpal. The radial carpal (fig. 57, 4) is a small somewhat cubical bone, wedged in between the manus and the radius and ulna. The ulnar carpal (fig. 57, 5) is a somewhat larger, more irregular bone, lying adjacent to the end of the ulna. It is deeply notched to receive the carpo-metacarpus. =The hand.= In the adult bird the hand is in a much modified condition; only the first three digits are represented, and the metacarpals are all fused with one another and with the distal carpalia to form the =carpo-metacarpus=. The most prominent part of the carpo-metacarpus is formed by the =second metacarpal= (fig. 57, 7), a stout, straight bone expanded at both ends. The =third metacarpal= (fig. 57, 8) is a more slender curved bone fused at both ends with the second metacarpal. The =first metacarpal= forms simply a small projection on the radial side of the proximal end of the second metacarpal. The =phalanges=. The first digit or =pollex= includes two phalanges, the distal one being very small and bearing a claw. The second digit includes three phalanges, the proximal one being somewhat flattened. The third digit has a single small phalanx. THE PELVIC GIRDLE. The bones constituting the pelvic girdle are not only as in other higher vertebrates ankylosed together forming the innominate bones, but are also ankylosed with a series of some seventeen sacral and pseudosacral vertebrae. The =acetabulum= (fig. 61, 5) with which the head of the femur articulates is incompletely ossified.