60 THE ROYAL SOCIETY OF CANADA 



Measurements of Dentary 



Total length externally • 393 mm. 



Height over coronoid process 195 



Length of inferior margin _• 300 



Length of predentigerous portion 53 



Height of predentigerous portion 114 



Thickness at base of coronoid process 97 



Length of alveolus 305 



Height from summit of 13th tooth to inferior edge 130 



Anterior edge of coronoid process horizontally to worn surface of teeth. . 54 " 



Maximum horizontal width of coronoid process 57 



Oblique width of upper end of coronoid process 58 



External height of 13th tooth 33 



Worn surface of 13th tooth, height 23 || 



Worn surface of 13th tooth, width 12 



Number of teeth 29 



The predentary is of the usual type and is sufficiently defined by 

 the figure and the following measurements : 



Measurements of Predentary 



Length in straight line from anterior end to posterior end of upper posterior 



process • • 238 mm. 



Length in straight line from anterior end to posterior end of lower posterior 



980 " 

 process '^°^ 



Total height, posteriorly 112 



Depth of posterior sulcus 84 



Oblique width from superior margin to lateral ridge 50 



Supero-posterior width between rami 39 



The sutures of the articular are very indistinct and the character 

 of the sphnial is sufficiently indicated by the drawing. 



General Measurements of Mandible 



Total length, tip of predentary to intero-posterior point of articular 670 mm 



Tip of predentary to anterior tooth 264 



Width between external points of surangulars 300 



Width between intero-posterior points of articulars 145 



Width of mouth between external cutting edges of teeth, posteriorly 115 



Width of mouth between external cutting edges of teeth, anteriorly 40 



From externo-posterior point of surangular to intero-posterior point of 



articular 1^3 



The anterior cervical vertebrae are similar in arrangement to 

 those figured by Lull for Triceratops prorsus (Monograph, page 47) 

 except that no trace is visible of the short anterior vertebra. There 

 seems to be only three co-ossified vertebrae as stated by Brown in his 

 Pescription of Monodonnts nasicornis} ^ 



1 Bull. Am. Mus. Nat. Hist., Vol. XXXVH, Art. X, p. 288. 



