In all the Cretaceous genera the carpal bones of each row are blended into a single bone, so that two bones are superimposed, which may be termed the proximal and distal carpals. One specimen shows by an indication of sutures the original division of the distal carpal into three bones; and the separated constituent bones are very rarely met with. Two bones of the three confluent elements contribute to the support of the wing metacarpal, and the third gives an articular attachment to the bone which extends laterally at the inner side of the carpus, which I now think may be the first metacarpal bone turned backward towards the humerus. The three component bones meet in the circular pneumatic foramen in the middle of the under side of the distal carpal. There is no indication of division of the proximal carpal in these genera into constituent bones. [Illustration: FIG. 43. CARPUS FROM ORNITHOCHEIRUS (Cambridge Greensand)] This condition is somewhat different from birds. In 1873 Dr. Rosenberg, of Dorpat, showed that there is in the bird a proximal carpal formed of two elements, and a distal carpal also formed of two elements. Therefore the two constituents of the distal carpal in the bird which blends in the mature animal with the metacarpus, forming the rounded pulley joint, may correspond with two of the three bones in the Cretaceous Pterodactyle _Ornithocheirus._ The width of a proximal carpal rarely exceeds two inches, and that of a distal carpal is about an inch and three-quarters. Two such bones when in contact would not measure more than one inch in depth. The lower surface shows that the wing had some rotary movement upon the carpus outward and backward. METACARPUS [Illustration: FIG. 44. METACARPUS IN TWO ORNITHOSAURS]