U, ulna; R, radius; c, cuneiform; 1, lunar; s, scaphoid; u, unciform; m, magnum; td, trapezoid; tm, trapezium.
In none of the existing, and in but few of the extinct types, are collar-bones, or clavicles, developed; and the scaphoid and lunar bones of the carpus are separate.
On the other hand in the Diplarthra, the tcl group to which the vast majority of modern Ungulates A i n belong, the second or lower row has been shifted altogether towards the inner side of the limb, so that the magnum is brought considerably into relation with the scaphoid, and is entirely removed from the cuneiform, as in most existing mammals.
The os magnum 1, lunar; sc, scaphoid; u, unciform; of the carpus articulates freely m, magnum; td, trapezoid; tm, with the scaphoid.
The humerus often has a foramen (entepicondylar) on the inner side of its lower end; the tibia and fibula may be separate or united; but the scaphoid and lunar of the carpus are also united, while the centrale is free.
In the carpus the scaphoid and lunar bones are united.
In the carpus the scaphoid and lunar are welded, but the centrale remains distinct.
In the Bathyergoidea the scaphoid and lunar of the carpus are separate, the tibia and fibula united and the clavicles normal.
The tibia and fibula are separate, but the scaphoid and lunar are united, and the clavicles are generally incomplete.
The three bones of the first row of the carpus (scaphoid, lunar and cuneiform) are subequal in size.