66 The Ottawa Naturalist. [October 



ilium is not present. The bones of this individual are splendidly pre- 

 served and occurred scattered over a small area in a gray, clayey 

 sandstone which is easily removed, leaving the surfaces in good con- 

 dition. The elements composing the top of the skull behind are pre- 

 served together otherwise the skull is naturally disarticulated. 

 Collection of 1916, Edmonton formation, Red Deer river, from 7 miles 

 north-west of Morrin, in sec. 16, tp. 31, R. XXI, on the west side of 

 the river, 90 feet above the level of the river. Cat. No. 2289. 



The drawings for the figures accompanying this article are the 

 work of Mr. Arthur Miles. 



Edmontosaurus regalis gen. et sp. nov. 



Type of genus and species. Skull, with the skeleton largely 

 represented. Cat. No. 2288. Discovered by L. Sternberg. 



Paratype. A nearly complete skeleton, including the skull. Cat. 

 No. 2289. Discovered by G. F. Sternberg. 



Geological horizon and locality. Edmonton formation (upper 

 Cretaceous), Red Deer river, Alberta, Canada. 



Generic and specific characters. Skull moderately elongate, high 

 and broad posteriori}*, flat in the frontal region, laterally compressed 

 behind a low, greatly expanded snout. Orbit large. A large, pocket- 

 like recess developed within the postfrontal, leading from the orbit. 

 Lateral temporal fossa restricted above. Palatine and pterygoid rising, 

 at a high angle, inward. Ectopterygoid external to the maxillary and 

 pterygoid, connecting the two. Mandible deep and strong, very 

 slightly decurved in front. Teeth with a rounded apical outline in 

 lateral aspect, keeled, and with smooth borders; in 48-49 vertical rows 

 in the dentary, and 51-53 in the maxillary. Ischium long, bluntly 

 pointed distally. Femur slightly longer than the tibia. Humerus 

 nearly as long as the ulna. Cervical and dorsal vertebrae opisthocoelus, 

 in a marked degree in the former. Dorsal spines of moderate size, 

 increasing slightly in height backward in the series. Sacrum composed 

 of eight vertebrae. Animal of robust build, about 40 feet long. 



Edmontosaurus approaches most closely Diclonius Cope, one of 

 the principal characters distinguishing the two being found in the 

 shape of the skull which in Edmontosaurus is high and in Diclonius 

 greatly depressed. The name Diclonius is here reserved for D. 

 mirabilis Cope, from the Lance formation of Dakota, sometimes 

 referred to as Trachodon mirabilis a genus and species insecurely 

 established by Leidy in 1856, on a tooth from the Judith River beds 

 of Montana. No characters can at present be assigned to Trachodon 

 beyond those derived from the single mandibular tooth which con- 

 stitutes the type. 



Edmontosaurus rivalled in size its bulky contemporary Hypacro- 

 saurus. It appears, however, not to have been as large as Prosaurolo- 



