POLYONAX. Ill 



Principal measurements of the type. 



Mm. 



Greatest length of portion of ilium preserved ; 1 142 



Estimated length of ilium when complete . 1 392 



Antero-posterior expanse of ischiac and pubic peduncles 342 



Greatest transverse diameter of ischiac peduncle '_ 150 



Distance from superior border of ilium to extremity of ischiac peduncle 212 



Transverse diameter of eighth dorsal from sacrum 132 



Vertical diameter of same 107 



Length of same 91 



Height of anterior zygapophyses above suture for centrum Ill 



Height of base of neural spine above suture for centrum 155 



Distance from capitular to tubercular facets 130 



The above description of the type of Agathaumas sylvestris, together with the original 

 and later descriptions by Professor Cope, makes it clear that the generic and specific distinc- 

 tions must rest on such characters as are to be found in the ilium, sacrum, posterior dorsals, 

 and ribs, and it will be well to bear this point in mind when we come to a discussion of the 

 synonymy, which will be taken up in that part of the present volume devoted to a revision of 

 the genera and species. 



Agathaumas milo Cope. 1874. 



Type (No. ?, American Museum of Natural History) consists of a sacral centrum and fragment of proximal end of tibia, 

 no longer determinable. 



Original description Bull. U. S. Geol. and Geog. Surv. Terr., vol. 1, No. 1, 1874, 1st ser., p. 10, footnote. 

 Cope, E. D., Bull. U. S. Geol. and Geog. Sun'. Terr., vol. 1, No. 2, 1st ser., p. 21; Rept. U. S. Geol. Surv. Terr., vol. 2, 1875, 



p. 58. 

 Nopcsa, F. Baron, Foldtani Kozlony, Budapest, 1901, vol. 31, p. 270. 



In a brief footnote on page 10 of Bulletin No. 1, first series of the Bulletins of the U. S. 

 Geological and Geographical Survey of the Territories, published in 1874, Professor Cope 

 names, without any description whatever, this and a number of other supposedly new Mesozoic 

 Reptilia. His remarks in this connection are as follows: 



In examining a collection from this formation, made by one of my assistants, I find a series of Mesozoic genera of verte- 

 brates as follows: Dinosauria, Oinodon [a misprint for Cionodon] arctatus, gen. et sp. nov.; Polyonax mortuarius, gen. et sp. 

 nov. ; Agathaumas milo, sp. nov. ; * * * 



On page 21 of Bulletin No. 2, first series, United States Geological and Geographical 

 Survey of the Territories, Professor Cope identifies the very fragmentary material constituting 

 the type of the present species as pertaining to Hadrosaurus occidentalis. His remarks in this 

 connection were as follows: 



Remains of species of Dinosauria were obtained at two localities in Colorado not many miles apart, the greater number 

 at one of them, from which also the crocodilian and turtle remains were derived. Those from other deposits consist of portions 

 of limb bones apparently of a single individual of gigantic size. The more abundant fragments are referable to three species. 

 A fragment of limb bone is very similar to portions from the other locality, and associated is a sacral vertebra of appropriate 

 size and characters. All of these were therefore referred provisionally to a single species under the name of Agathaumas 

 milo, but are here described under Hadrosaurus occidentalis. 



It is thus clear that, according to Cope, Agathaumas milo Cope became a synonym of 

 Hadrosaurus occidentalis Leidy. Whether or not this latter determination was correct the 

 fact remains that A. milo is a nomen nudum, and the fragmentary nature of the type is such 

 as to preclude an adequate description. The species should therefore be discarded. 



POLYONAX Cope. 1874. 



Type species P. mortuarius. 



Original description Bull. U. S. Geol. and Geog. Surv. Terr., vol. 1, No. 1, 1874, p. 10, footnote. 

 Baur, G., Science, vol. 17, 1891, p. 217. 

 Cope, E. D., Ann. Rept. U. S. Geol. and Geog. Surv. Terr, for 1873 (pub. 1875), pp. 448, 451-452; Bull. U. S. Geol. and Geog. 



Surv. Terr., vol. 1, No. 2, 1st ser., 1874, pp. 7, 21, 24; Rept. U. S. Geol. and Geog. Surv. Terr., vol. 2, 1875, pp. 58, 63-64; 



Am. Naturalist, vol. 22, 1888, p. 1109; Science, vol. 13, 1889, p. 290; Am. Naturalist, vol. 23, 1889, p. 715. 



