130 BULLETIN 110, UNITED STATES NATIONAL MUSEUM. 



Tn 1896 ' the same author gives a compilation of what has been written before 

 of Ormthomimus; the plate illustratmg the genotype 0. velox is republished, and a 

 text figure illustrating the terminal j^halanx of the manus of 0. sedens shows the 

 character of that bone. 



Tn 1897 - this same compilation was republished, with little change. In 1902 ^ 

 Zittel included Ormthomimus under the familj' Megalosauridae without definition 

 or remarks for so doing. In 1902 * Lambe described the new species Ormthomimus 

 alius from the Belly River formation of Red Deer River, Alberta, Canada, and 

 contributed considerable to our knowledge of the skeletal anatomy. 



In 1911 ^ Zittel, without comment, included Ormthomimus in the family 

 Compsognathidae. 



In 1917 " Osborn gave the first adequate knowledge of the skeletal anatomy 

 of a representative of this family, the description and illustrations bemg based on a 

 beautifully jireserved skeleton from the Belly RiA^er formation as exposed along 

 the Red Deer River, Alberta, Canada. This specimen on inadecjuate characters 

 is made the genotj^ie of the new genus Struthioinimus. He also gives a most 

 interesting discussion of its probable habits, accompanied by life restorations 

 illustrating the views set forth. 



Professor Osborn says : 



Ornithomimus, as a geologically more recent stage, is distinguished (from Siruthiomimus) by the 

 loss of metatarsal V in the pes, for which no facet remains, and other characters. 



Quoting further from the above author, the pruicipal reason for separating 

 these genera is given in the following: 



It is noteworthy that only a single genus or species of dinosaur is known to pass from the Monclonius- 

 Ceratops zone (Belly River, Judith River) into the Triceratops-Torosaurus zone (Hell Creek, Lance, 

 Denver). This is the genus Trachodon. The known carnivorous and herbivorous dinosaurs under- 

 went profound modifications and it is not probalile, therefore, that the Ornithomimidae remained 

 generically unchanged. 



I do not believe the above reasons as enumerated by Osborn justify the estab- 

 lishment of a new genus. That the genus Ornithomimus does range through from 

 Judith River to Lance time now appears to be indicated by a recent comparison 

 of the type specimen of Ornithomimus sedens of the Lance formation (consisting 

 of the articulated pelvic arch, sacrum, and 12 anterior caudals) with the Belly 

 River specimen (Struthiomimus) . It fails to disclose differences that could by 

 any possibihty be construed to be of more than sjiecific importance. In this 

 connection it is also of interest to note that 14 specimens of the Ornithomimidae 

 from the Triceratops-Torosaurus zone, listed by and apparently available to Osborn 

 for comparison, failed to disclose generic characters beyond those quoted above. 



In the light of our present knowledge, therefore, I shall for the present consider 

 Struthiomimus to be a synonym of the earlier described Ornithomimus. 



1 Dinosaurs of North America, pp. 204-206, pi. 58, text fig. 49-52, 1896. 



» Vertebrate Fossils of the Denver Basin, p. 518, 1897. 



3 Textbook on Paleontology, English Translation, vol. 2, p. 230. 



< Contr. Canadian Paleont., vol. 3, pt. 2, pp. 50-53, pis. 13, 14, and 15, figs. 1-8, text flg. 11, 1903. 



5 Grundzuge du Palaeontologie, vol. 2, p. 28:3, 1911. 



« Amer. Mus. Nat. Hist., Bull. 35, pp. 73S-761, pis. 26, 29, text figs. 3-8, 11-16, 1917. 



