i 4 2 E. C. CASE 



direction and deeply concave from side to side. The shape is best 

 shown in Figs. 8 and 9. The outer of the two cotyli is the larger, 

 and is nearly twice as wide as the inner. It is impossible to dis- 

 tinguish the bones of this region as separate elements. 



The outer face of the jaw is rugose, and near the anterior end of 

 specimen No. 1076 it is marked by a depression evidently for the 

 attachment of powerful muscles. This depression at first seems 

 due to crushing, but there is no evidence of breaking, and the same 

 thing occurs on both jaws. There is no such depression in the jaws 

 of specimen No. 1075. The symphasis of the jaws was sutural, 

 narrow, and nearly vertical. 



There are eleven of the wide molariform teeth, and one empty 

 alveolus in the posterior portion of the jaw. Anterior to these there 

 is a single large incisor tooth, and the empty alveoli for four more, 

 so that, if there was a small peg-like tooth at the posterior end corre- 

 sponding to the small tooth at the end of the maxillary series, there 

 were in all seventeen or eighteen teeth. The whole series of teeth 

 is slightly concave from before backward and convex toward the 

 middle line. The teeth are worn on the outer half only, to corre- 

 spond with the wear of the inner side of the maxillary teeth. The 

 posterior teeth are the wider, and after the posterior eight they rapidly 

 narrow toward the front. 



The shoulder girdle (the description of the shoulder and pelvic 

 girdles is taken from specimen No. 1075). — The shoulder girdle con- 

 sists of the interclavicle, clavicles, scapulae, coracoids, precoracoids, 

 and cleithra. The scapula, coracoids, and precoracoids are closely 

 united. This, with the condition of the bones, makes it impossible 

 to trace the exact form of the separate elements. The form of the 

 three united bones is very similar to the scapula-coracoid figured by 

 Broili as belonging to Naosaurus (Broili, 1904, Figs. 5, 5a, Plate 

 XIII). This determination of the bones is erroneous, as it is very 

 far from the condition of the Pelycosauria and closely approaches 

 that of the Diadectidae here figured. The scapula is rather elongate 

 and narrow vertically. Its posterior end terminates in a rather sharp 

 point. The edge of the articular cotylus is very prominent, and the 

 face looks backward rather than outward. In the Pelycosauria 

 there is a foramen which penetrates the shaft of the scapula on the 



