THE UPPER TRIASSIC OP WESTERN TEXAS. 



27 



have retained their normal position. The restoration of the skeleton has been accom- 

 plished by placing the bones in their most evident position, with such checks as their 

 original position afforded. 



The skull. — In many of its characters the skull resembles that of the Phytosauria, 

 but differs so radically in others that it must be placed at least in a separate suborder. 

 The close occlusion of the sutures and the condition of preservation has made the 

 determination of the most of the sutures impossible. The surface of the skull has been 

 most carefully cleaned with a needle and has been treated with acid to remove the 

 pyrite and the other matrix. It has been repeatedly examined under a binocular 

 microscope, so that the author feels certain that all possible traces of the sutures have 

 been made out. 



Fig. 7. — Skull of Desmatosiwhus spurensis. 



A. Upper surface. X 0.3. B. Lateral surface. X 0.3. C. Posterior surface. X 0.3. D. Lower surface of pos- 

 terior portion. X 0.6. E. Lateral surface of wall of brain-case. X 0.6. 



bs., basisphenoid; ps., parasphenoid rostrum; ot., otic channel; ais., alisphenoid; pro., prootic; ot, otic opening; 

 op., opisthotic; II-XII, outlets of cranial nerves. 



