lO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6^ 



present specimen leads the writer to suggest its possible identification 

 with the present genus; Hatcher regarded it as belonging to a smaller 

 and distinct individual from the type of that species and he also ob- 

 serves : " I describe and figure this element in this connection not 

 out of regard for any certain additional characters it may furnish 

 distinctive of the present genus and species [Monoclonius crassus] 

 but rather for the information which it affords relative to the homol- 

 ogies of certain cranial elements in the Ceratopsia as a group." 

 The great similarity of the horn-cores with those of Brachyceratops 

 lends much color to the above suggestion. 



MEASUREMENTS ^,„_ 



Greatest length of skull, about 565 



Greatest breadth of skull, estimated 400 



Expanse of frontal region at base of brow horn cores 90 



Greatest width of nasals 58 



Length of interparietal along median line 3i5 



Height of nasal horn core above border of narial orifice 125 



Greatest width of postf rontals 80 



Greatest length of combined post- and prefrontals 126 



NOTE ON HYPACROSAURUS 



I wish to announce the discovery in northwestern Montana, in 

 beds equivalent to the upper part of the Belly River formation, of 

 the Trachodont reptile Hypacrosaurus^ A considerable portion of 

 the skeleton (Cat. No. 7948, U. S. Nat. Mus.) of one individual 

 was recovered, and at this time (the specimen not being entirely 

 prepared) I am unable to distinguish it specifically from the type 

 and only known species, H. altispinus Brown, from the Edmonton 

 Cretaceous of Canada. 



^Barnum Brown: A New Trachodont Dinosaur Hypacrosaurus, from the 

 Edmonton Cretaceous of Alberta. (Bull. Amer. Mus. Nat. Hist., Vol. 32, 

 1913. pp. 395-406.) ' 



