798 H. G. SEELEY ON NEW SPECIES OE 



dinally, but less than -^ inch in length. Its hinder margin is distant 

 ■fa inch from the transverse occipital margin, and its anterior bor- 

 der is about l T \j- inch from the extremity of the snout. Behind the 

 foramen the parietal, postfrontal, and squamosal bones are expanded 

 as in the marine Chelonia ; but in Procoloplion the occipital region 

 is closed posteriorly, as in Dinosaurs and Dicynodonts, which is not 

 the case in the Chelonia ; and the roof of the skull is encroached 

 upon by the backward position, obliquity, and large size of the 

 orbits. The orbits are elongated ovals, the hinder margins of which 

 are in a line with the back of the foramen parietale, fa inch in length 

 and fa inch in depth from the frontal to the malar. The anterior 

 margin of the orbit appears to be pierced with a large lachrymal 

 duct. The orbits appear to be margined by the maxillary and 

 malar bones below ; the postfrontal, which is very large, by its ex- 

 pansion seems to have filled in the vacuity between the parietal and 

 squamosal ; it forms the back of the orbit. The frontal divides the 

 orbits ; where narrowest it is about fa inch wide ; from the foramen 

 parietale to its transverse junction with the nasal bones it measures 

 fa inch. The prefrontals appear to be moderate, to form the upper 

 anterior borders of the orbits, and to extend forward to the nasal 

 bones ; but as the substance of the bone is broken away and only 

 obscure sutural lines remain to indicate its limits, this statement is 

 made with some reserve. There are some indications that the orbits 

 were parted by a septum, and probably they were conditioned much 

 as are the orbital cavities of Hatteria. I have evidence that the 

 base of the orbit in this genus was formed by a palatal plate, and 

 that the eye must have reached back to the front wall of the some- 

 what large brain-cavity. The chief difference of the external 

 orbital region from that of such a lizard as Plestiodon consists in 

 the large size and backward prolongation of the orbit. The inter- 

 space between the orbit and narine is -^1 inch. The portion of the 

 skull anterior to the orbit has an aspect as of side-to- side compres- 

 sion. The nares are small, oval, and vertical, and lie between the 

 premaxillaries in front, the maxillaries behind, and the nasals 

 above. The narrow premaxillaries extend up so as to be embraced 

 by the nasal bones, and only form a narrow band anterior to the 

 nares. The teeth in each of the premaxillaries are four in number, 

 two prehensile teeth close together in front of the nares (one in 

 each bone) and three behind. In the maxillary bone of the right 

 side are six teeth. These teeth are subcylindrical, and terminate 

 in sharp conical points ; they are placed close together, so that the 

 expanded bases are almost conical. The hindermost tooth is 

 fa inch from the extremity of the snout. The teeth have a central 

 pulp- cavity which extends high up into the crown. At the base 

 of each maxillary tooth appear to be many germs of successional 

 teeth, which extend backward obliquely from the bases of each. 

 Behind the teeth the maxillary bone appears to terminate in a 

 downward process. The malar bone is about fa inch deep in front, 

 but widens behind by rising so as to narrow the orbit posteriorly, 

 and looks obliquely outward and upward. At the back of the 



