. 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. 33 represents the foramen figured by Gilmore*, but if so it was entirely concealed within the symphysis. The upper border of the bone is rounded and helps to form the inner wall of the posterior part of the alveolar groove. Behind this it thins, and its upper border slopes away till it terminates in a point about the level of the coronoid process. The outer face is applied to the dentary in front, and to the co
. 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. 33 represents the foramen figured by Gilmore*, but if so it was entirely concealed within the symphysis. The upper border of the bone is rounded and helps to form the inner wall of the posterior part of the alveolar groove. Behind this it thins, and its upper border slopes away till it terminates in a point about the level of the coronoid process. The outer face is applied to the dentary in front, and to the coronoid and angular behind. Ventrally the anterior portion of the bone appears below the dentary and forms the lower edge of the mandible, but farther back it thins out and its lower border slopes up to its posterior termination, the posterior third or so of the bone lying entirely on the inner face of the ramus. The surangular {, text-figs. 20, 21) forms the upper border of the hinder portion of the mandible. It is a long bone, consisting of a pointed anterior prolonga- Text-fig. Left surangular bene of Ojphthalmosaurus : A, iuner side; B, outer side. (R. 2740 about ^ nat. size.) , facet for union with the angular; , facet for union with the articular bone; , articular surface; c, c'., coronoid processes ; , facet for union with the coronoid bone; ,, surfaces of union with the dentary ; foi-., foramen on outer surface of bone; (j., groove running forwards from the foramen ; t., tubercle at hinder end of articular surface. tion and a much broader posterior articular portion. It is partly concealed in front by the overlapping of the dentary, but below this the surface is exposed and bears a very deep longitudinal groove (g.) into which a foramen (for.) opens posteriorly. The inner face of the anterior portion is flattened and covered first by the dentary and behind this by the anterior expansion of the bone here called the coronoid (go7'.)
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectreptile, bookyear1910
