The tablet exhibits eight examples of a bone which at its distal end is attached to the marginal apicular articulation of the distal carpal, thence extending proximally, and terminating in an articular facet for the third bone of the fore-arm, so as to overlap laterally both of the other carpals. The bone is compressed, is three times as wide as thick, and in outline sub-quadrate with a distal talon. On the inner side it is flat, and on the outer side above the talon it is concave vertically and convex transversely in such way that the side of the bone to which the distal articulation is adjacent is thicker than the other side, and sometimes bent at a sharp angle. The talon on the inner aspect of the bone is flat and continuous with the quadrate side, but on the outer aspect it is separated from the side by an elevated transverse thickening, distally to which the bone is compressed, and rounded into the adjacent parts. The talon extends over more than half of the distal end of the bone, and constitutes with the remainder of the distal end, the distal articulation, which is flat from front to back, and concave from side to base. The proximal articulation is cupped and extends over the whole proximal surface; it is at right angles with the sides of the bone. Both the inner and outer sides exhibit small pneumatic foramina. No. 8 differs from the other specimens in its sub-triangular lateral outline, and general less complex modifications. The Carpus of the Cambridge Ornithosaurians at first sight is not easily compared with that of Birds; Birds having but one bone between the radius and the metacarpus. But that one bone in the Ostrich, for instance, is not unlike in form to the proximal carpal of Pterodactyle; while the proximal end of the metacarpus presents so close an analogy with the distal carpal of the Pterodactyle, that even were it not easily demonstrated that the bone in Birds commonly called the metacarpus is a carpo-metacarpus[R], it would be strong evidence for such a determination. In Birds there is a small lateral bone between the ulna and carpo-metacarpus which is evidently homologous with the lateral carpal of our Pterodactyles, and so, since this lateral carpal of the Ostrich is the pisiform bone, it results that the lateral carpal of Pterodactyle is the pisiform bone also. From this follows a conclusion of the first importance in the interpretation of the hand. The fine hair-like metacarpals of the Pterodactyle are on the side towards the pisiform bone, while the great wing-metacarpal is on the side towards the index finger. [Footnote R: They separate without difficulty in the Chicken.]