| OCR Text |
Show 224 PROF. H, G. SEELEY ON THE [Mar. 21, where the foramen is distinct, ovate, and larger (on the left side of the head), and is between the malar, postorbital, squamosal, and quadrate. It is a linear gap in the bones in one specimen. It/ is much smaller than the vacuity in the side of the skull m Palceohatteria. The extension of the foramen downward to the quadrate bone involves no substantial difference from the British Museum specimen R. 1999, so that the name Procolophon laticeps may be used for that specimen, in preference to P . trigoniceps used in Phil. Trans. 1889, pi. 9. The Teeth.-Usually the mandible is in close contact with the skull, so that the teeth are not seen, except on their external or internal aspects. The incisors are rather longer and stouter in aspect than the maxillary or molar teeth. They are conical, but flattened on the inner surface, which carries a few vertical ridges. I have failed to obtain evidence of implantation in sockets by making a vertical section. Text-fig. 33. Palate of Procolophon eunexceps, showing the molar teeth; from Donnybrook. A specimen in the British Museum, R. 794, was developed in fruitless search for the occiput, but now shows with exceptional clearness the structure of the quadrate region and the palate (text-fig. 33). The pterygoids and vomera are shown bearing teeth, the palatine bones, palatine plates of the maxillary bones, and the maxillary are seen on the palate. The most interesting feature of the dentition is the crowns of the maxillary teeth, which unexpectedly have a transverse molar form, as in the lizard Tejus. They are six in number on each side, wide transversely, with distinct inner and outer cusps, and with the inner and outer triturating surfaces separated by interspaces which appear to have received |
