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Show 1893.] OSTEOLOGY O F LEPIDOTUS A N D DAPEDIUS. 561 The membrane-bones of the cranial roof do not extend backwards quite so far as the occipital border, the narrow space thus left being covered by the supratemporal plates. There are two principal pairs of bones, the short parietals (Plate X L I X . fig. 1, pa.) behind, and the longer frontals (fr.) forwards, not bilaterally symmetrical, and uniting in all directions by very irregular angulated sutures. More anteriorly there would be the nasals, but Head-bones of Lepidotus latifrons ; Oxford Clay, Peterborough. One half nat. size. 1. Exoccipital. 2. Pro-otic. 3. Parasphenoid, inferior aspect. 3 a. Para-sphenoid, superior aspect. 4. Eight quadrate, inner aspect. 5. Lett quadrate, outer aspect. 6. Metapterygoid. bpt„ basipterygoid process; /., foramen ; p., process. these are not satisfactorily known. The long and narrow squamosal element (sq.) on each side reaches as far forwards as the anterior extremity of the parietals, but not so far backwards as the hinder margin of these bones. It is considerably overlapped behind by the supratemporal series of plates, and on the inner |
