THE UPPER TRIASSIC OF WESTERN TEXAS. 



71 



lower edge runs upward and forward for a short distance and then turns directly back- 

 ward. The posterior end is broken away and lost; so the total length of the process is 

 uncertain, but it was evidently quite long. The lower edge of the process is turned 

 inward, as in No. 7322, but in this specimen it looks almost directly downward rather 

 than down and back. The cotylus is not so deep and the faces for the ischium and pubis 

 meet in a sharp angle. On the inner face (see plate 13, fig. B) the upper part of the blade 

 of the ilium is deeply concave; the lower edge of the concavity marks the upper edge of 

 the articular surface for the sacral ribs. Near the anterior end there are two deep, 



FIG. 27. 



A. Lower surface of interclavicle, No. 7442, U. of Mich. X 0.3. 



B. Right ilium, outer side, No. 7322, U. of Mich. X 0.3. 



C. Left ilium, outer side, No. 7244, U. of Mich. X 0.3. 



D. Left ilium, outer side, No. 7333, U. of Mich. X 0.3. 



E. Left ilium, outer side, No. 7266, U. of Mich. X 0.3. 



rugose pits below this edge, marking the place of insertion of the distal ends of the sacral 

 ribs. Below the posterior pit there is a wide rugose surface which received the posterior 

 half of the distal end of the second rib. Above this surface the lower edge of the concave 

 surface extends back as far as the posterior end of the broken bone; it evidently extended 

 to the extremity in the perfect specimen. The whole bone is much heavier than in 

 No. 7322, the anterior edge just below the anterior process of the upper edge being excep- 

 tionally thick. 



No. 7333 differs from either of the previously described forms in that the height 

 is much less relative to the length (fig. 27 D; plate 12, fig. F). The length of the anterior 



