418 J. B. Hatcher — Two New Ceratopsia. 



mosal is elongate, and just posterior to" the quadrate groove it 

 is pierced by a large fenestra. The anteroinferior angle is 

 little produced and there is no quadrate notch, the inferior 

 border in this region describing widely an open concavity. The 

 parietals are broad and thin and, on either side of the median 

 line about 235 mm in front of the posterior border, there is an 

 elongated fenestra with a longitudinal diameter of 150 mm and a 

 greatest transverse diameter of 52 mm . This fenestra is com- 

 pletely enclosed on the right side, but on the left the parietal is 

 injured in this region. In the drawings it has been restored 

 from the right side. The supra-temporal fossa is elongate. 

 There is a single median postfrontal f on tan ell e as in Tricera- 

 tops, but posteriorly this gives origin to two deep channels, one 

 on either side. These run backward along the surface of the 

 parietal and terminate in two small circular fontanelles, condi- 

 tions very similar to those which obtain in Torosaurus. 



Measurements of the type. 



" Distance from anterior end of rostral to posterior of squa- 

 mosal .... 1990 mm 



Distance from anterior end of rostral to anterior of -orbits 845 

 " " inferior border of orbit to lower end of jogal 363 

 " " posterior border of nasal opening to ex- 

 tremity of beak ._.. 614 



Distance from posterior border of orbit to posterior sur- 

 face of horn core x _- _T 175 



Distance between anterior borders of orbits . . . . 340 



Circumference of supraorbital horn cores at base 610 



" " " . " , mm. above orbit... 340 



Vertical diameter of orbits 165 



Antero-posterior diameter of orbits. __> 125" 



[Note. — This genus is most nearly allied to Triceratops and is 

 distinguished therefrom mainly by the much smaller rostral bone ; 

 by the absence of a nasal horn, which in all species save T. 

 obtusus is fairly well developed ; by the very erect, short, robust, 

 supraorbital horn cores which seem to take their origin much 

 further back with relation to the orbit ; by the concavity of the 

 frontal region between the orbits and by the peculiar form of the 

 postfrontal fontanelle. The general proportions of the skull 

 resemble Triceratops rather than the contemporary genus Toro- 

 saurus, in which the great frill so preponderates over the compara- 

 tively abbreviated facial region. The parietals resemble those of 

 Triceratops except for the presence of the small fenestras on 

 either side of the median line. 



The squamosals differ from those of Triceratops in the con- 

 formation of the lower border, which lacks the quadrate notch, 

 and in the presence of the unique fenestra. 



