. A descriptive catalogue of the marine reptiles of the Oxford clay. Based on the Leeds Collection in the British Museum (Natural History), London ... Reptiles, Fossil. OPHTHALMOSAUEUS. 23 frontal and prefrontal bones. The inner face of the bone, which is concave from above downwards, is marked by a series of longitudinal ridges running forwards from the nasal opening. The maxilla (test-fig. 13) is a small bone compared with the premaxilla and in no case seems to have borne teeth, though the dental groove begins in its anterior portion. The bone, as a whole, is a shuttle-shaped structure, with
. A descriptive catalogue of the marine reptiles of the Oxford clay. Based on the Leeds Collection in the British Museum (Natural History), London ... Reptiles, Fossil. OPHTHALMOSAUEUS. 23 frontal and prefrontal bones. The inner face of the bone, which is concave from above downwards, is marked by a series of longitudinal ridges running forwards from the nasal opening. The maxilla (test-fig. 13) is a small bone compared with the premaxilla and in no case seems to have borne teeth, though the dental groove begins in its anterior portion. The bone, as a whole, is a shuttle-shaped structure, with the upper and inner surfaces deeply concave from above downwards. The posterior prolongation bears on its outer face (text-fig. 13, A) an elongated concave, grooved surface {) for. a' d^. Eight maxilla of Oplithdlmosaurus: A, outer side ; B, upper side ; C, iuner side ; D, vertical section at the line D-D in fig. 0. (E. 2180, i nat. size.) ;., dental groove; , facial portion of bone; , facet for jugal ; , facet for lachrymal; , border of external nares ; n,f., facet for nasal; 2^^., palatine plate; ], facet for premaxilla : , processes on palatine border. union with the overlapping jugal: there may have been a little play between the two elements. In front of this the outer face of the bone is flat above and gently convex below: its upper border is produced upwards into a blunt triangular process, the outer face of which is overlapped by the lachrymal, with which it unites in a short strong suture {) along its upper edge. In front of this projection the upper border of the bone is rounded and forms part of the lower edge of the nasal opening {). Anterior to this, again, there is an elongated and roughened facet («•/•) for union with. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectreptile, bookyear1910
