94 THE CERATOPSIA 



The chasmosaur skeleton in the Royal Ontario Museum, No. 5499, was also found by the 

 expedition of 1926, on the east side of Red Deer River, two miles south of Steveville, Alberta, and 

 125 feet above the river level. Therefore, it was 75 feet below the Chasmosaurus brevirostris 

 skull. Whether this means 75 feet of intervening strata is not clear. This skeleton is, as yet, unde- 

 scribed, but varies from those in Ottawa in minor details only. The skull has been partially 

 restored, and with a rather short muzzle somewhat suggestive of brevirostris, but there detailed 

 resemblance ceases, for there are no brow horns, only the rugose area above the nearly circular orbit 

 as in the Yale skull. The nasal horn, on the other hand, is stout, straight, and abruptly truncated. 

 The crest is deeply emarginate, the effect of which is heightened by the very large epoccipitals at 

 the postero-lateral corners of the crest. This skull and that on the skeleton No. 2280 at Ottawa, 

 show the deepest emargination, but otherwise, the resemblance is not very close. The value of this 

 character in itself is difficult to determine. In view, however, of the high specialization of the 

 entire crest, I should imagine that minor individual variations were common — no two crests, in fact, 

 no two skulls, are ever exactly alike. 



Chasmosaurus brevirostris, n. sp. 



PI. VII, A 



Holotype: No. 5436 R.O.M., Toronto; skull without lower jaws, the rear of the crest slightly restored. 



Horizon: Belly River formation. 



Locality: On the west side of Red Deer River, Alberta, three miles southwest of Steveville, along the railway 



grade, at an elevation of 200 feet above the river. 

 Collector: University of Toronto expedition of 1926. 



This specimen conforms to belli, except that the muzzle is very short and deep, more as in 

 Monoclonius, and the nasal horn is large and curves somewhat backward, although inclined forward 

 at the base. The brow horns are like the nasal but smaller. The last epoccipital on the squamosal is 

 markedly larger than in any other specimen, and the broadly elliptical orbit is almost vertical. The 

 right epijugal is sharp and trihedral, like that of Pentaceratops. There were nine epoccipitals 

 borne on the squamosal. 



Chasmosaurus kaiseni Brown 33 



PI. V, A; Text Fig. 38 



Holotype: No. 5401 A.M.N.H.; a splendidly preserved skull without lower jaws. 

 Horizon: Belly River formation. 



Locality: About 12 miles below Steveville, on the Red Deer River, Alberta. 

 Collector: American Museum expedition of 1913. 



The specific characters are as follows: Muzzle very long, terminating in a relatively small 

 rostrum. Nasal horn of medium length, consisting apparently of three elements, one median, 

 grooved on its posterior face, the others anterior and lateral to the first, the lateral ones being highly 

 rugose, and the entire horn unlike that of any other known chasmosaur ; brow horns very large for 

 a Belly River ceratopsian, since those of no other skull, except Eoceratops canadensis and a chas- 

 mosaur to be described below, approach them in size. They rise above the anterior half of the 

 orbit, curve outward, and sharply forward, then upward, and bear abundant vascular impressions. 

 It is these horns alone that show any approach of Chasmosaurus to Ceratops (see p. 97). The 

 orbit is very large, and broadly oval, with the long axis inclined upward and backward at an angle 

 of 45°. The rear of the crest is but slightly emarginate, with the usual large epoccipitals just 



33 Brown, B., 1933, B. 



