12 8 THE CERATOPSIA 



as such the result of disease, or injury, or both. Surely they can have no taxonomic significance. 

 One wonders how many of the peculiarities of this skull, except perhaps the absence of the nasal 

 horn, may be due to this diseased condition which, in affecting the behavior of the animal including 

 the carriage of the head, reacted upon the entire organism. 



The number of maxillary teeth is 24, less than the usual number. 



Diceratops may be of sub-generic, but hardly of generic rank, for it is clearly a modified 

 Triceratops, possibly the culmination of the evolutionary trend seen in Tricerato-ps obtusus and out 

 of its lineage. The species hatcheri I would consider valid. 



"INADEQUATE" SPECIES OF TRICERATOPS 



The three or four remaining species of Triceratops, I have called "inadequate" because of 

 insufficiency of the type in each case, for while each form may be absolutely valid, it is impossible 

 to define it in terms of the common factors we have been using. They will have to remain ill 

 defined until more perfect material is found in each instance. 



Of these, Triceratops galeus, consisting of a single nasal horn core, No. 2410 U.S.N. M., 

 Hatcher has already discarded as based upon insufficient evidence. He says, however, that it 

 resembles the nasal horn of Torosaurus gladius more than any known species of Triceratops, and 

 may have pertained to that genus and species. It also resembles fairly closely that of the skull, 

 No. 5 1 1 6, on the mounted skeleton of Triceratops in the American Museum, which Hatcher never 

 saw, and which has been referred tentatively to elatus. The evidence is too slender for determina- 

 tion of the species under discussion, and galeus, which is from the Denver beds of Colorado, must 

 remain a nomen nudem pending further discovery. 



Triceratops alticornis Marsh 87 



Holotype: 88 No. 4739 U.S.N. M.; pair of brow horns with the communicating cranial bones. 

 Horizon: Denver beds. 



Locality: On the banks of Green Mountain Creek, near Denver, Colorado (Fig. 2, loc. 17). 

 Collector: G. L. Cannon, Jr., 1887. 



Here, the brow horns alone must determine the specific characters, which makes a clear defini- 

 tion impossible. The main distinction of these horns lies in their curvature, for while anteroverted 

 at an average slope for Triceratops, they are otherwise straight in lateral aspect, but slope outward 

 and then upward in a single curve, when viewed from the front. Aside from this, there is nothing 

 to distinguish these horns from those of several other species. Here, again, the validity of this 

 species must await further discovery. 



Triceratops sulcatus Marsh™ 



Holotype: 90 No. 4276 U.S.N.M.; fragmentary skull, vertebrae, etc. 

 Horizon: Lance formation, No. 16 in the sequence. 

 Locality: Niobrara County, Wyoming. 

 Collector: J. B. Hatcher, 1890. 



There is, in addition, the plesiotype, No. 4286 U.S.N. M., 91 consisting of a pair of brow horns 

 with the connecting cranium, which has been sectioned for the brain. This is number 26 from the 

 top in the stratigraphic series and therefore considerably lower than the holotype. 



87 Marsh, O. C, 1887, pp. 323-324 (Bison alticornis). 

 Marsh, O. C, 1889, B, pp. 174-175 (Ceratofs alticornis). 



88 Hatcher, Marsh, Lull, 1907, Fig. 106, p. 115. 



89 Marsh, O. C, 1890, B, p. 422. 



90 Hatcher, Marsh, Lull, 1907, p. 133-134, Figs. 112-113. 

 111 tbid., Fig. 113. 



