132 The Ottawa Naturalist. [Jan. 



reduced in Torosaurus by a broadening of the parietal framework, 

 and the much smaller supraorbital horn-cores which are upright 

 instead of being curved forward. 



The finding of the skull of Protorosaurus belli completely 

 does away with any idea as to the specific identity of this species 

 with Mono clonius canadensis, Lambe, also from the Belly River 

 Cretaceous of Alberta; a consideration at no time entertained 

 by the writer. 



With the skeleton of P. belli were found well preserved 

 impressions of the integument.* These impressions seem to 

 refute the hitherto generally accepted idea of the presence in 

 the Ceratopsia of bony scutes such as are found in the Stego- 

 sauridas, notably in Euoplocephalus (Stereocephalus) tutus, Lambe, 

 from the Belly River formation. We now know that the in- 

 tegument of P. belli was of the. same general character as that 

 of the trachodonts, and probably the other horned dinosaurs 

 were similarrv covered. 



The natural impressions of the integument|of P. belli consist 

 of smooth polygonal surfaces, ranging in diameter from about 

 one-eighth of an inch up to one inch and one-eighth, indicative 

 of the presence in the living animal of non-imbricating scales or 

 plates, fitting closely to each other, and having generally five 

 or six sides. The plates themselves are not preserved but they 

 have impressed their shape in the sandstone (moulds) from which 

 natural caste have been made by the matrix replacing the plates. 



The larger plates have a flat or very slightly convex surface 

 and are defined by a circumscribing groove. The smaller sized 

 plates have the form of low or flattened tubercles and were 

 apparently present over a large area. The larger plates are 

 assembled and increase in size toward a somewhat central one 

 which is the largest, and which may be polygonal or rounded in 

 outline. There is evidence of polygonal plates at least two inches 

 in diameter and of others with a nearly circular outline equally 

 large. In the larger sized plates the sunken peripheral margin 

 has a crinkled appearance due to the presence of short grooves 

 at right angles to, and ending at the edge of the plate. 



The impressions of the plates so far seen are mostly from 

 the trunk region in the neighbourhood of the shoulder where the 

 increase in size seems to be from below upward. Other im- 

 pressions from lower down on the body are of the small tubercles 

 apparently indicating an absence here of the larger sizes of 

 plates. 



The collection of 1913 from the Belly River formation on 

 Red Deer river also includes natural moulds and casts of large 



* This specimen, with skin impressions, was discovered by Mr. Charles H. Sternberg, in 

 chair* ol the Geological Survej rti irate palaeontological expedition <>t 1913. 



