. Carnegie Institution of Washington publication. PERMO-CARBONIFKROUS VERTEBRATES FROM NEW MEXICO. 31 pophyses, laterally. The outer edge of the upper end of the transverse process is just on a line with the outer edges of the anterior and posterior zygapophyses. The articular face runs down to the anterior edge of the centrum. The ninth vertebra is the first with a complete neural spine; this is oval in sec- tion throughout, with the anterior and posterior edges slightly contracted; the upper end is not rugose nor expanded; it terminates in a flat, smooth face. From the tenth to the sixteenth
. Carnegie Institution of Washington publication. PERMO-CARBONIFKROUS VERTEBRATES FROM NEW MEXICO. 31 pophyses, laterally. The outer edge of the upper end of the transverse process is just on a line with the outer edges of the anterior and posterior zygapophyses. The articular face runs down to the anterior edge of the centrum. The ninth vertebra is the first with a complete neural spine; this is oval in sec- tion throughout, with the anterior and posterior edges slightly contracted; the upper end is not rugose nor expanded; it terminates in a flat, smooth face. From the tenth to the sixteenth vertebra there is little or no change in form. The maximum width of the neural arches is attained in the tenth and retained to the fifteenth. The upper ends of the transverse processes do not reach beyond the line of the zygapophyses, and beyond the tenth they shorten very rapidly, until in the last of this series they form only very slight prominences on the sides of the centra. The neural spine of the tenth is similar to that of the ninth, but does not exhibit a slight anterior curvature visible in the anterior one; this curv- ature may be due to accidents in fossilization or may be the last remnant of a. Fig. 19.—Diusparactus zeiws Case. Lateral view of the last eleven presacral vertebne, X ^2. decided forward curvature of the spines in the cervical region. On the posterior face of the thirteenth the broken surface shows the edges of distinct hyposphene and hypantrum articulations. The posterior edges of the neural arches of the last vertebra in this series are nearly straight vertically; they descend almost directly from the base of the neural spines and do not overlap the anterior portion of the succeeding vertebrae, as in Diadectes. The centra are short, without keels on the mid-line, but are somewhat narrowed below. The seventeenth vertebra is slightly displaced from the sixteenth, but is held in place by matrix. It shows a very decided change in form from the precedi
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