382 Annals of the Carnegie Museum. 



of Dysgaiius. He did not characterize the genus Trachodoii, and after- 

 wards abandoned it. (Proceedings Academy, Phila., 1868, p. iqq.)'"'' 

 We have already shown that Leidy had not abandoned the genus and 

 had fully characterized it, accompanying his descriptions with splendid 

 illustrations of the material at his confiiiand. There would seem 

 therefore little doubt as to the synonymy of Diclouiiis and Traclwdon. 

 The splendid skeleton of Tracliodon (^Dicloniiis) mirabilis discovered 

 by Drs. Wortman and Hill in the Laramie of South Dakota enabled 

 Professor Cope to more fully characterize that genus than it had been 

 possible for Dr. Leidy to do. A careful comparison between this 

 skeleton and the remains from Haddonfield, New Jersey, of Hadro- 

 saiirus foulkii should determine whether or not the latter genus is a 

 synonym of Trachodoii. 



Claorhyncluis trihednis^^ was applied by Cope to a rostral and pre- 

 dentary bone (locality and horizon not given) which he considered as 

 pertaining to the A^kiathainnidac but which -^vould appear from the 

 description given to more properly belong to the Trachodontidae. 



In 1889 '^ Professor Cope proposed still another genus and species, 

 Pteropelyx gralUpes for these dinosaurs, based upon a portion of a 

 skeleton discovered by Mr. J. C. Isaac near Cow Island, Montana, on 

 the Upper Missouri River some forty miles below the mouth of the 

 Judith River. The locality and horizon are essentially the same as 

 those t'rom which Dr. Hayden procured the types of Traclwdon and 

 there can be no doubt as to the identity of the two genera. In 1892^'' 

 Cope considered Pteropelyx and Claosaiiriis as synonyms. In the 

 paper last cited he says (p. 758): " Pteropelyx Cope — This genus was 

 described by me in The American Naturalist for October, 1889, p. 

 904 (published March 5, 1890). It has been subsequently named 

 by Marsh, Claosaun/s, in the /American Journ. Sci. Arts, for May, 

 1890 (p. 243)." The discovery of more complete material of 

 Pteropelyx has shown the identity of that genus and Trachodoii. 



In 1889 Professor Marsh proposed two new species — Trachodon 

 {Hadrosaiiriis) l>rez<iceps d.\\d T. {Hadrosaiiriis) paiicideiis, founded on 

 fragments of jaws from the Bad Lands on the Judith River, in Mon- 

 tana, the same locality as that which yielded the type of the genus.'' 



'3 .See Proc. Phil. Acad. Sci. 18S3, pp. 93-107, Plates IV. -VII. 



i*See Am. Nat., 1892, p. 757. 



'•^ Ibid., 1889, p. 904. 



'6 Ibid., 1S92, p. 758. 



17 See Am. Jom-. Sci., Vol. XXXVII., April, 1S88, pp. 335, 336. 



