I am indebted to W. Reed, Esq. of York, for the opportunity of making a notice of this species, which closely resembles O. capito.
The species which follow were separated in the "Index to the Ornithosauria," &c. as a different genus. That proposal might still be sustained, for these massive truncated jaws are unlike the spear-shaped jaws of many of the species. And to the minds of some readers the forms already described will arrange themselves in groups which not improbably indicate genera. But a re-examination of the type Pterodactylus simus (Owen) has convinced me that it is a lower jaw, and therefore it affords no evidence of the presence or absence of the peculiar front premaxillary teeth which characterize nearly all the Cretaceous species.
XXV.
| Case. | Comp. | Specimen. | |
| J | c | c | 16 |
Ornithocheirus simus (Owen).
The palate is 23/4 inches long, and at the second pair of teeth about 7/8ths of an inch wide. It is fractured at the end through the fifth socket, and at the side along the palatal groove. The first pair of teeth is smaller and closer together than the others. The palatal interspace between the second pair is 3/8ths of an inch; between the third pair, which are large teeth, it is 1/2 an inch. The sockets are sub-circular, and are not separated from each other by wider interspaces than their own length. In front is a long triangular rugose area, convex from above downward, a distance of 11/2 inch; and concave from side to side, a width above of rather more than 1/2 an inch. Below this the flattened sides converge to a blunt keel; where, fractured, the jaw is 21/2 inches deep. There are several fragments of species allied to the last; one has the triangular area in front very small, only half as high as in the type and very narrow, for the sides are gently rounded into it. It is marked by short longitudinal furrows, impressed vessels I think, while in O. simus the surface is irregularly rough. The first pair of teeth are much larger than in O. simus; they are longer, more conical, and circular, and separated by as wide a space as the second pair. There is not much to found a species on, but as it appears to be quite distinct from O. simus, it is named O. Carteri. Another fragment, with the area very long, is marked O. platyrhinus. But a sufficiency of species has been indicated to make known the Ornithosaurian fauna of the Cambridge Greensand. And the detailed description of critical types and of the other parts of the skeletons is beyond the general osteology of the tribe, and will rather belong to a memoir in which this flock of Pterodactyles will be restored to their living forms.
A fragment of the lower jaw of a large Ornithocheirus has been obtained from an outlier of the Upper Greensand at Rocken End in the Isle of Wight. It appears to indicate a distinct species. It is 21/2 inches long, and shows three large teeth still preserved in their sockets. The extreme width outside the third pair of sockets is nearly 2 inches. The sides, which are slightly concave from above downward, converge so as to give the broken end a triangular outline. In front is a small sub-triangular area, deeply scored with vascular markings; below this the outline slopes obliquely backward, and the two sides there round convexly into each other. The first socket is 7/16ths of an inch long, the tooth coarsely striated, and like the others elliptical; the interspace between the first and the second teeth is 5/16ths of an inch. The second tooth, probably immature, is an inch in length, smooth, and like the third traversed in front and behind by a slight lateral ridge; at the base it measures 5/16ths of an inch from front to back. The third tooth is rather less than 5/8ths of an inch from front to back. The interspace between the first and second sockets, which the teeth do not entirely fill, is more than 1/4 of an inch. The posterior margin of each socket is elevated into a sort of collar.