H.MCHF.R: Gf.NERA and SpF.CIKS oI ri<A( IIODONTID.K. 385 



Hadrosaurus foulkii Leidy, Proc. Phil. Acad. Sci., December, 

 1858, pp. 215-218 



Hadrosaurus minor Marsh, Proc. Phil. Acad. Sci., January, 

 1870, p. 2. 



Hadrosaurus if ipos Co^e, Trans. Am. Phil. Soc, 1870, p. 122. 



Ornithotarsus immanis Cope, Proc. Am. Phil. Soc, 18S9, p. 117. 



Hadrosaurus cavatus Qo\)t, Trans. Am. Phil. Soc, 1871. 



Hadrosaurus agilis Marsh, Am. Jour. Sci. and Arts, April, 1872. 



Cionodon arctatus Cope, Bull. U. S. G. S. Terrs., No. i, 

 1874, p. 2. 



Cionodon stcnopsis Cope, Vertebrata of the Cretaceous Formations 

 of the West ; An. Rep. U. S. G. S. Terrs., Vol. II., 1875, pp. 57-63. 



Polygonax mortuarius Cope, An. Rep. U. S. G. S. Terrs, for 1S73, 

 pub. 1875, pp. 451-452. 



Diclonius pentagonus Cope, Proc. Phil. Acad. Sci., 1876, pp. 



253-255- 



Diclonius perangulatus Cope, Proc. Phil. Acad. Sci., 1876, pp. 



253-255- 



Diclonius calamarius Cope, Proc. Phil. Acad. Sci., 1876, pp. 



253-255- 



Hadrosaurus breviceps Marsh, Am. Jour. Sci., April, 1889, p. 335. 



Hadrosaurus paucidens Marsh, Am. Joiir. Sci., April, 1889, p. 336. 



Pteropelyx grallipes Cope, Am. Nat., October, 1889, p. 904-905. 



Trachodon longiceps Marsh, Am. Jour. Sci., May, 1890, p. 422. 



Claosaurus (^Hadrosaurus^ agi/is Marsh, Am. Jour. Sci., May, 

 1890, p. 423. 



Claosaurus annectens Marsh, Am. Jour. Sci., May, 1892, p. 453. 



C/aorhynchiis trihedrus Co^e, Am. Nat., Sept. 1892, p. 757. 



A careful examination of the original descriptions and figures of the 

 types of the ten genera and twenty species enumerated above, shows 

 that there should be a great reduction in each and that the ten genera 

 which have been proposed should be reduced to two Trachodon Leidy 

 and Claosaurus Marsh, while the remaining eight genera should be 

 treated as synonyms of Trachodon, which should also be made to in- 

 clude T. (^Claosaurus) annectens Marsh ; while the smaller Claosaurus 

 agilis described by Marsh from the Kansas chalks may still be con- 

 sidered as pertaining to a distinct genus. 



Doubtless many of the species are also synonyms but this can only 

 be determined by a careful comparison of the types. 



