THE OTTAWA NATURALIST 



VOL. XXIV. OTTAWA, DECEMBER, 1910 No. 9 



NOTE ON THE PARIETAL CREST OF CENTROSAURUS 

 APERTUS AND A PROPOSED NEW GENERIC 

 NAME FOR STEREOCEPHALUS TUTUS.* 



By Lawrence M. Lambe, F.G.S., F.R.S.C, 

 Geological Survey, Canada. 



The defensive frill or crest of Centrosaurus, so singular in 

 its general form and contour, has lately been found to be even 

 more grotesque than it appeared to be at the time of its discovery. 



This crest, made up almost exclusively of the coalesced 

 parietals, was originall}^ (1902 r) described as appertaining to 

 the species Monoclonius dawsoni, Lambe, but was later (1904J) 

 made the type of the genus Centrosaurus. When found by the 

 writer in 1901 in the Judith River (Belly River) fonnation, on 

 the west side of Red Deer river. Alberta, a short distance below 

 the mouth of Berry creek, a straight, laterally compressed bone, 

 tapering toward one end was with it immediately beneath its 

 lower surface. This bone was at the time supposed to be a horn- 

 core and was described as such in the original reference to the 

 crest and when the genus Centrosaurus was established, the 

 parietal crest and the so-called nasal horn -core constituting the 

 type material of the new genus. The discovery during the past 

 summer of the true nature of the "horn-core" is of interest and 

 calls forth the following remarks. 



In mv description of the crest in the paper published in the 

 Transactions of the Royal Society of Canada, vol. X, 1904, the 

 following references to the hinder portion of the specimen are to 

 be found: "The parietal expansion, for the purpose of descrip- 



Communicated. by permission of the Director of the Geological 

 Survey. 



fGeological Survey of Canada. Contributions to Canadian Palae- 

 ontology, vol. III. (quarto), part II., On Vertebrata of the Mid-Cre- 

 taceous of the North-west Territory, p. 58, 1902. 



JThe Ottawa Naturalist, vol. XVIII., p. 81, On the squamoso- 

 parietal crest of two species of homed dinosaiirs from the Cretaceous of 

 Alberta. 



