. Bulletin of the Department of Geology. Geology. Two New Species of Fossil Turtles from Oregon. 239 The bone thickens until it reaches a thickness of 7 nun. where the suture just named meets the entoplastron. At the inner posterior angle the bone is only 3 mm. thick. In lot No. 2179 there is a portion of a left hyoplastron which lacks the free border, but which in the portions represented is identical with the specimen above described. I regard it, there- fore, as belonging to the same species and to the same formation. In this lot are included also a portion of the right epiplastron (F
. Bulletin of the Department of Geology. Geology. Two New Species of Fossil Turtles from Oregon. 239 The bone thickens until it reaches a thickness of 7 nun. where the suture just named meets the entoplastron. At the inner posterior angle the bone is only 3 mm. thick. In lot No. 2179 there is a portion of a left hyoplastron which lacks the free border, but which in the portions represented is identical with the specimen above described. I regard it, there- fore, as belonging to the same species and to the same formation. In this lot are included also a portion of the right epiplastron (Fig. 2), the first right peripheral bone (Fig. 3), a right peri- pheral, apparently the eighth or ninth, and some other fragments. The epiplastron has the border which joined its fellow of the other side missing, so that it is impossible to determine accurately the width of the anterior lip of the plastron. However, this bone has been used in making the restoration of the front of the plas- tron, as seen in figure 1. Figure 2 shows this bone as seen from below. It resembles closely the same bone in 0. guttata, except that its upper side was not so deeply excavated as in the latter species. According to the restoration the lip had a breadth of about 34 Figure 2. Figure 3. The free borders of the epiplastron are subacute. Seen from the side, this border runs forward to the gulo-humeral sulcus and then turns rather abruptly downward, forward and inward. From the acute edge the bone thickens rapidly, until a thickness of 7 mm. is attained. The gulo-humeral sulcus has probably continued backward on .the entoplastron. A piece of the thickened border of the xiphiplastron of this specimen is present. It extends from the junction with the hyoplastron to just behind the femoro-anal sulcus. Most of the free edge is broken away, but enough remains to show that it was acute. It thickens gradually until, at the inner border of. Please note that these images are extracted from scanned pag
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