150 The Ottawa Naturalist. [Feb 



The lower surface of the skull has not yet been freed from 

 the matrix, and the remainder of the skeleton is also in the state 

 in which it was brought from the field and awaits description, 

 but the skin impressions found with the remains of this individual 

 have been described and figured by the writer in the paper above 

 mentioned, in which the genus Chasmosaurus is defined. 



When found, the front part of the head above and in advance 

 of the midlength of the maxillaries had gone to pieces through 

 weathering, as had also the left side of the face as far back as 

 the outer margin of the squamosal. The plane of weather 

 had not reached the rami of the lower jaw, which are present, 

 but the predentary is missing. The large squamoso- varietal frill 

 is in a particularly excellent state of preservation. On the right 

 side the orbit and jugal are intact, and both supraorbital horn- 

 cores are present. This specimen was found with the dorsal 

 surface uppermost, in a bed of clayey sandstone impregnated 

 with iron. It has apparently suffered little distortion. The 

 right jugal is pressed outward to some extent, and the squa- 

 mosals, particularly toward their outer border, appear to be less 

 inclined downward than they should be. The mandibular rami, 

 as also the right quadrate and quadrato-jugal, were slightly 

 displaced, but without distortion. 



The genus Chasrrosaurus is regarded as ancestral to 

 Torosaurus of Marsh from the Laramie of Wyoming, U.S.A. 

 Its main characters, as already defined, are as follows: 

 Skull large, broadly triangular in superior aspect, with 

 a narrow, abbreviated facial portion, and a broad and 

 greatly extended posterior crest ending squarely behind. 

 Coalesced parietals forming a slender framework enclosing large 

 sub-triangular fontanelles. Squamosals very long and narrow 

 with a scalloped free border. Epoccipitals present. Supraorbital 

 horn-cores small, upright. Supratemporal fossae of moderate 

 size. Postfrontal fontanelle present. Jaws robust . Teeth 

 large, of the ceratopsian type. Body covered with non- 

 imbricating, small plate-like, and smaller tubercle-like scales. 



In this skull of C. belli, discovered by Mr. Charles H. 

 Sternberg, the length is \h times the breadth, the di 

 forward of the anterior end being given with a fair degree of 

 accuracy by the mandibular rami. The very great size of the 

 crest or neck-frill, as compared with the rest of the head, is one 

 of the most striking features of the skull, the length of the former 

 to that of the latter being in the proportion of about 2-h to 2 

 The frill is almost square, while the abbreviated facial portion 

 narrows rapidly to the front. 



The crest, composed of the coalesced parietals and th< 

 squamosals, is remarkably flat; it extends backward and 



