2 University of Michigan 



grooves. The clavicles are decidedly convex at the posterior end 

 and the center of sculpture is presented laterally rather than dowTi- 

 ward. The loss of the broken tips of the slender processes of the 

 anterior ends of the bones was slight and they did not meet in the 

 median line; the intervening space must have been filled with 

 cartilage. The scapular processes of the clavicles are represented 

 by their base; the posterior end is about 12 mm. broad and the 

 plates rapidly diminish to extreme thinness. The process lies in 

 the posterior third of the cla\'icle and about 18 mm. within the 

 outer edge. It is probable, but not certain, that the processes did 

 not extend beyond the posterior edge of the bone. 



A few typicairy stereospondylus vertebrae and fragments of 

 skull bones have been found in the same locality. 



The measurements are as follows: 



Mm. 



Length of the interclavicle 328 



Breadth of the interclavicle 290 



Length of the clavicle 285 



Breadth of the clavicle 165 



The only specimens found in the United States with which this 

 specimen can be compared are the interclavicle described by Lucas 

 {Proc. U.S. Xat. Mus., XVII [1904], 193-95) from the Triassic, 

 five miles east of Tanner's Crossing, Little Colorado River, Arizona, 

 and an imperfect interclavicle found near Tuckers Springs, on the 

 road from Holbrook to Leupp, Arizona, which probably belongs 

 to the same genus and species as Lucas' specimen. As shown in 

 Plate III of Lucas' paper, his specimen resembles the one here 

 described fairly closely but differs somewhat in proportions, being 

 430 mm. in length and 300 mm. in breadth; also the coarse reticu- 

 late sculpture of Lucas' specimen covers a proportionately larger 

 part of the surface of the plate. 



In comparison with the thoracic plates of Metoposaiirus diag- 

 nosticus Frass from the lower Keuper of Hansweiler near Stuttgart 



