The fragment is 1-7/8 inch long. The second and third sockets, with their interspace, measure 1-1/8 inch. On the opposite side the first socket is intermediate in position between the first and second. Though not likely, it is just possible that this might be the premaxillary bone of O. eurygnathus. XVIII. Ornithocheirus brachyrhinus (Seeley). Case. Comp. Tablet. =J= _c_ 24 This fragment of a premaxillaiy bone is fractured behind the sockets for the third pair of teeth. It is 1-1/8 inch long, and shows one pair of small teeth in front and two pairs of large ovate teeth on the palate. The first pair are divided from each other and from the second pair by films of bone; and the second pair are separated from the third by rather more than half the length, of the third socket. Behind the third pair of sockets the palate is 5/8ths of an inch wide; it is flattened, and has a blunt moderately elevated mesial ridge. Behind the second pair of sockets the jaw is 5/8ths of an inch high; behind the third pair of sockets it is 3/4ths of an inch high; the distance between the places of measurement is 1/2 an inch. The sides are flat and converge to a rounded nose. The jaw is rounded from side to side in front, and the outline of the top of the nose rounds over the blunt termination of the snout above the teeth on to the palate. In the shortness of the nose it somewhat resembles the _?P. giganteus_ (Bowerbank), but the jaw attenuates less rapidly, is truncated, and has larger teeth. XIX. Ornithocheirus enchorhynchus (Seeley). Case. Comp. Tablet. =J= _c_ 25 This species nearly resembles _O. brachyrhinus,_ from which it differs in larger size, with a relatively wider palate, which is without a keel, and in a larger front pair of teeth. It approximates towards _O, colorhinus_, but is smaller, and wants the rugose lunate area over the front pair of teeth characteristic of that species. There are many varieties or species nearly related to this type, but from their imperfect preservation and the small part of the head which they represent, it is not possible to give descriptions of them. XX. Ornithocheirus eurygnathus (Seeley). Case. Comp. Series. Tablet. =J= _c3_ 16 1