1913 J The Ottawa Naturalist 113 



formed the posterior border of the orbit and met the jugal and 

 the squamosal below and the parietal behind. The upper 

 orbital rim is thickened and overhangs the orbit, and rises 

 conspicuously above the level of the flat postfrontal surface 

 between the orbits. The lachrymal probably forms the an- 

 terior rim of the orbit and the prefrontal the overhanging upper 

 margin of the same. Set well back posteriorly on the raised 

 ridge above the eye-opening is a small, shallow, smooth depression, 

 irregularly oval in outline, which indicates the position of an 

 extremely small, or incipient, supraorbital horn-core, which 

 appears to have been present as a separate ossification and to 

 have become detached. 



The jugal had much the same shape as in Triceratops; it 

 was pointed below, and, in its upper part, extended to either 

 side, anteriorly to overlap the maxilla and posteriorly to meet 

 the squamosal. It formed the lower rim of the orbit and the 

 whole of the upper margin of the lateral temporal fossa, which 

 was enclosed below by a forwardly directed process from the 

 squamosal. The thin upper end of the quadratojugal is wedged 

 between this process and the quadrate, which is seen in the 

 lateral aspect of the skull, passing beyond the quadratojugal 

 to effect a union with the under surface of the squamosal. 



The squamosal is well developed, of a fair size, roughly 

 quadrangular in shape, and a little broader than long on its 

 main outer surface. At the middle of its anterior breadth it 

 sends forward an outwardly flat process, which encloses the 

 lateral temporal fossa below and behind. Its lateral free mar- 

 gin is smooth, rounded, and regularly undulating with five 

 somewhat vertically compressed convexities to the outline. 



The neck-frill in its anterior half is saddle-shaped. The 

 surface of the coalesced parietals between the fontanelles is 

 equal to their transverse diameter and is flatly convex across 

 and slightly concave longitudinally. The bone surrounding the 

 fontanelles is very thin at the edge. Between these openings 

 it remains moderately thin, but toward the lateral free edges 

 and posteriorly it becomes thickened, especially so at the bases 

 of the large processes and along the posterior border. Behind 

 each fontanelle the surface of the bone rises into a rough, 

 obliquely placed short ridge or keeled boss. Proximally the 

 posterior processes are somewhat vertically compressed, but 

 outwardly they become more nearly circular in transverse sec- 

 tion. The median portion of the coalesced parietals is con- 

 tinued forward, in advance of the fontanelles, as a distinct 

 raised surface with parallel sides, >:o meet the postfrontals, where 

 it probably formed the hinder margin of the postfrontal fon- 

 tanelle. This anterior part of the parietal is damaged, but on 



