The only species which it resembles is O. brachyrhinus, but differs from that in the flatter, narrower palate, which makes a greater angle with the rostral keel, and in the smaller teeth, which are separated by wider interspaces.

XIV.

Case.Comp.Series.Specimen.
Jc2111

Ornithocheirus nasutus (Seeley).

A fragment of a premaxillary bone 6 inches long. It somewhat resembles O. Cuvieri in the aspect of the palate, but the jaw is more elongated, and expands from side to side at the anterior end. The teeth are opposite to each other in front, but become irregular after the sixth. The palate measures behind the second pair of sockets 3/4ths of an inch, behind the third pair it is a sixteenth of an inch wider, behind the ninth pair half an inch, and in the last two inches it begins to widen again. A sharp keel arises behind the second pair of sockets and becomes more prominent to behind the tenth pair, when the channel which accompanies it on each side seems to disappear. The first pair of teeth, which look forward, is smaller than the second and third pairs; they are closer together than those which follow. The third sockets are 7/8ths of an inch from the tip of the snout. Then follow three smaller, more circular teeth, which are separated from each other by interspaces as long as the sockets. The back of the sixth sockets are 21/4 inches from the tip of the snout. Then follow two larger more elliptical sockets; after which the sockets become smaller and are separated by longer distances, that between the 10th and 11th pairs is nearly 3/4ths of an inch.

The height of the jaw behind the second pair of sockets is 5/8ths of an inch, behind the sixth sockets 15/16ths, behind the tenth sockets 11/4 inch. In front, the nose has the aspect of being compressed from above downward, and behind it is compressed from side to side. The sides are flattened and round into a narrow rostral ridge which is depressed at the anterior end.

XV.

Case.Comp.Tablet.
Jc21

Ornithocheirus polyodon (Seeley),

This species is founded on the anterior end of a premaxillary bone; in form not unlike O. Fittoni. It is 5/8ths of an inch wide; the lateral margins approximate very slowly, and in front it appears to be truncated. It is an inch and a quarter long, and in that space were on each side six large round teeth, almost as close together as they could be, five on the palate and a pair in front. The terminal two are no wider apart than the rest, and point more forward. A moderate, sharp, median ridge descends in the flattened palate, making its lateral halves a little concave. The front termination of the palate is slightly reflected upward. The jaw, which is 1/2 an inch deep behind, tapers to its termination more rapidly than does O. Fittoni. The flat sides similarly converge, and form a well-rounded ridge, which does not get blunter in front. From their close approximation, it results that the tooth-sockets are entirely above the palatal surface, so that they are better seen from the side of the jaw than from the palate.