. Carnegie Institution of Washington publication. FIG. 2.—Buettneria perfecta. A. Upper (inner) view of the bones of the basicranial region. , descending process of the squamosal; , open- ing of cavity for the inter- nal carotid artery; x, outlet for the tenth cranial nerve. Other lettering as in figure 1. B. Upper view of the left quadrate ramus of the pterygoid. Lettering as in previous figures. opening of the arch on the parasphenoid; beneath it a second pit passes forward and slightly inward and is imperforate. The apices of the two pits are separated by a thin wall. The third par
. Carnegie Institution of Washington publication. FIG. 2.—Buettneria perfecta. A. Upper (inner) view of the bones of the basicranial region. , descending process of the squamosal; , open- ing of cavity for the inter- nal carotid artery; x, outlet for the tenth cranial nerve. Other lettering as in figure 1. B. Upper view of the left quadrate ramus of the pterygoid. Lettering as in previous figures. opening of the arch on the parasphenoid; beneath it a second pit passes forward and slightly inward and is imperforate. The apices of the two pits are separated by a thin wall. The third part of the triangular base is formed by the lower part of the anterior rising process. The upper part of this rising process is somewhat crumpled; it is impos- sible to interpret the appearance exactly, for the distortion gives the appearance of reduplication, as if the bone were made up of superimposed laminse or, which seems very improbable, of separate thin bones. On the posterior edge of the quadrate ramus is the posterior rising process. Its inner end originates just posterior and external to the second pit described above; it reaches nearly as great a height as the anterior one, but there is no indication that it was ever attached to the roof above; in the specimen there is quite a space between the two. This process is shown by Quenstedt1 as reaching up to the squamosal in Cyclo- tosaurus (Mastodonsaurus) robuslus. Fraas,2 however, shows the plate of much less height in Cydotosaurus posthumus. Watson, in his figure after Fraas, draws it much The outer ends of the two processes unite apparently without suture and clasp the inner and part of the posterior face of the quadrate. Into the deep cleft between the two processes descends the process from the squamosal. The relations of these processes 1 Quenstedt, F. A., Die Mastodonsaurier iin griinen KeupersandsU'ine Wurtemberg'ssind Batrachier, Tubingen, 1850, pi. 3, fig. 10. 2 Fraas, E., Neue Labyrinthodonten aus der
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