1913] The Ottawa Naturalist 115 



As with most Ceratopsia, the outer and upper surfaces of 

 the skull are marked by vascular grooves, notably so on the 

 horn-core, the postfrontal above, and the posterior processes. 



The magnificent specimen here described has been skill- 

 fully prepared for stud)- by Mr. Charles H. Sternberg, who 

 discovered it last summer on Red Deer river, Alberta, on the 

 south-west side of the river, about twelve miles below the mouth 

 of Berry creek. The plates are reproductions from excellent 

 photographs taken by Air. Geo. G. Clarke. 



The genus Styracosaurus is distinguished from Ceratops, 

 Marsh, by having incipient instead of well developed supra- 

 orbital horn-cores, by the shorter squamosals, and by the 

 intraparietal fontanelles of moderate size, instead of greatly 

 enlarged ones enclosed by the squamosals and parietals together. 



From Monoclonius, Cope, it differs in its greater size, the 

 smaller fontanelles of the frill, the larger squamosals, and in 

 having a straight, upright nasal horn instead of one which curves 

 backward. 



In Styracosaurus the shape and position of the nasal horn- 

 core, the spike-shaped outgrowths from the back of the frill, 

 the long postfrontal fontanelle, and the great size of the supra- 

 temporal fossae are additional characters separating this from 

 all other known genera of Ceratopsia. 



It is not possible to arrive at a definite conclusion regarding 

 the generic and specific affinities of Monoclonius sphenocerus, 

 Cope, from Montana, on account of the fragmentary condition 

 of the material on which this species is based, and the very 

 small part of the skull represented. The general resemblance 

 of Cope's specimen, which includes the nasals, the nasal horn- 

 core and the left premaxilla, to the corresponding parts of 

 Styracosaurus albertensis suggests the advisability of referring 

 the Montana species to the genus Styracosaurus. It is likely, 

 however, that the species are not the same. In so far as a 

 comparison can be made between M. sphenocerus and Styra- 

 cosaurus albertensis it is seen that in Cope's species the nasal 

 horn-core is farther forward on the nasals, is proportionately 

 shorter, and more laterally compressed, with a much greater 

 antero-posterior diameter at the base. The nasals in front of 

 the horn descend rapidly instead of rising conspicuously before 

 they curve downward, and the nasal opening is larger and placed 

 more under the horn. These differences are regarded as prob- 

 ably indicating a specific but not a generic distinctness. 



Measurements. Feet. Inches. 



Maximum length of specimen from midway 



between the points of the back processes . . 6 1 \ 



Greatest breadth of same across the processes 4 8h 



