On the inside surface of the bone there appear to be small muscular attachments in front of and behind the great tuberosity. The area between the spine and the inner surface is sometimes flattened, sometimes gently convex. With well-marked distinctive characters in the inferior tuberosity, the pre-tuberous emargination and the thick rounded form of the bone, the Pterodactyle scapula is intermediate in character between that of a mole, a bird, and the crocodile; wanting the sabre shape of the bird's scapula, it also wants the wide expanded form of the scapula of the Crocodile, but resembles the latter in the direction and degree of developement of the spine. This modification is probably due to the outward direction and clavicular function of the coracoid, as well as to the raptorial habit of the organism. In no living Reptile is there a scapula to be compared with that of the Pterodactyle, for besides the free end being expanded, in the crocodile, it is also thin and squamous and the bone makes a continuous curve with the coracoid as in struthious birds, and not a sharp angle as in Pterodactyles. The "spine" in crocodiles is on the anterior border of the bone and directed upward and backward, while in Pterodactyles it is on the posterior border and directed upward and forward. In the Chameleon the scapula is more elongated and narrow, narrower in proportion to its length than in Pterodactyle, but becomes rapidly wide at its union with the coracoid. It is curved in length so as to fit on to convex ribs. A scapula presenting some resemblance to Pterodactyle is found in certain Liassic Ichthyosaurs. Among mammals a straight elongated narrow scapula is rare. The mole however has a scapula of this kind somewhat cylindrical in its proximal half and not much expanded at the free end, on which there is a small spine. The anterior emargination above the glenoid cavity in Pterodactyle is entirely mammalian, as is the anterior tuberosity above the emargination, for it entirely corresponds with what in ruminants, pachyderms and many mammals would be named the coracoid process. If that process is accurately determined it is difficult to say what this is. In birds there is often a prolonged process on the inner side of the coracoid, which however extends interior to other parts of the scapula, and to this the furculum is attached. Such traces of a spine as are to be detected in the swan conform to the Pterodactyle. No bird has the scapula cylindrical, even struthious birds only making an approximation to such a condition; and no birds have the scapula so straight. The bone is more avian and mammalian than reptilian; and more avian than mammalian but with strong distinctive characters of its own. 17 specimens of the humeral ends of scapulæ are exhibited. Nos. 1, 4, 6, 7, 8, 9, 11, 13, 14, 15, 17 are left scapulæ. Nos. 2, 3, 5, 10, 12, 16 are right scapulæ. The tablet of the distal ends of scapulæ comprises 6 specimens. Fore-Limb. HUMERUS.