38 



NEW REPTILES AND STEGOCEPHALIANS PROM 



The neural spine of the fifth is low, thin, and broad, but posterior to this one the 

 spines of the vertebrae increase in height, become thinner at the base, transversely, and 

 elongate antero-posteriorly, and develop a knob or expansion at the apex. The 

 transverse processes rise progressively toward a horizontal position and increase in 

 length and thickness. On the sixth vertebra is seen the beginning of a ridge running 

 from the upper outer angle of the posterior face of the centrum to the base of the 

 transverse process; this continues to increase in importance until on the eighth it is 

 continued on to the lower face of the process as a thin supporting ridge inclined backward, 

 and the cross-section of the process is that of a T-beam. In the same manner the 

 capitular process increases in thickness and weight, but not in length. On the ninth 

 vertebra this process is over a centimeter in its two diameters, and a low, sharp ridge 

 runs from its upper face upward near the anterior face of the centrum, until it joins the 

 ridge on the lower face of the transverse process at the level of the base of the neural 

 canal. 



Fig. 11. — Desmatosuchiis spurensis. 

 H. Posterior view of a dupHcate tenth (?) vertebra, No. 7504, U. of Mich. X 0.6. 



In all these vertebra the neural arch is deeply excavated between the zygapophyses 



left nn^nf hV;" posteriorly, so that a considerable portion of the neural canal is 

 left uncovered between the vertebrae. 



the n^^lIXltT ^?i!''!°' uJ^^ T^^ ^"'" ^^^ f°^"d i«°l^t«d, with the exception of 

 the one reckoned as the twelfth and a few in the mid-dorsal region. They have been 



&tThronV;Sm^^^ '^' '--■ ^^- -^y ^^ -- '-. ^^t if can hardly 

 thin and^fb/S!.'^'^ reckoned as the tenth the zygapophysial processes are broad and 

 Interior edte till ? ""'"r^ horizontal. The transverse process is broad above; its 



TheTseclon nrfhi'' "'' ^ '""' ^' ,\'^' ''"'''' °^ ^^' ^^'^ «f the anterior zygapoph^es. 

 ihe T-section of the process is well developed. On this vertebra a ridge extends back- 



