A fragment of premaxillary bone, well distinguished from every other specimen, except one in the collection of Mr Reed of York, which is here named _O. Reedi_. It is a large head, with larger teeth than any known species. The jaw is truncated in front, with a rugose vertical area in front reaching 1-3/4 inch high from the palate, on which the usual front pair of teeth are not seen. At the angle of this front area with the palate is a large elliptical tooth 9/16ths of an inch wide, and behind it, with an interspace of 3/16ths of an inch, is a socket measuring 10/16ths of an inch in length; the next interspace is about 1/8th of an inch, and the next nearly circular socket is 5/16ths long; then another interspace of 1/8th of an inch, and another and a smaller tooth. The palate appears to have been channelled. The sides of the jaw are flat, or slightly concave, and where fractured above, are 3 inches high. Above the rugose vertical area of the snout, is an area, concave from back to front, reaching up to the rostral keel; it is flat from side to side behind, and convex from side to side in front. So much as is preserved measures 1-3/4 inch in length, and appears to be relatively narrower than in O. Reedi. XXIV. Ornithocheirus Reedi (Seeley). The anterior part of an upper jaw has flattened slightly concave sides, which converge above so as to form boundaries of (1) a flat triangular area which looks anteriorly, and of (2) an oblong area, traversed by a mesial groove, which looks upward and forward and is concave from back to front. In the lower half of the truncated triangular anterior termination are the remains of the stumps of the two anterior teeth; they are oval in outline, 9/16ths of an inch high, and 7/16ths of an inch wide; they are parted by an interspace nearly 1/4 of an inch wide, which becomes concave vertically as it rounds on to the palatal surface. All the front triangular surface above the teeth is rough: its entire height is about 1-1/4 inch, and is nearly as wide across the base. The side rounds a little into the concave median upper surface, and into the triangular front; so much as is preserved measures 2-1/2 inches high, and 1-3/8 inch long. The palatal surface, which is very small and badly preserved, is 1-3/4 inch wide behind, but gives no indication of further widening. On its outer border are seen two large circular teeth 5/8ths of an inch in diameter; they are separated by a median palatal interspace of 7/8ths of an inch. Where it is fractured behind, the specimen shows the sockets of another pair of teeth behind these, with an interspace of 1/4 of an inch in the antero-posterior direction. The palate is convex. The superior oblong area is concave in length as well as transversely. It makes a great angle with the triangular front of which it is the upward continuation; so much as is preserved extends 1-1/2 inch in length; it is about 1/2 an inch wide.