APPENDIX. 



Art. XL— The Skull of Torosaurus; by O. C. Marsh. 

 (With Plates II and III.) 



In this Journal for September last, the writer described a 

 new and remarkable genus of Ceratopsidce, represented by two 

 well-marked species.* In the type specimen on which the 

 genus was based, the greater portion of the skull is preserved, 

 and this presents so many points of interest, that a figure of it, 

 one-twentieth natural size, is here given in Plate II. The 

 second species is represented also by the skull, which, although 

 not complete, supplements the type in several important re- 

 spects, and figures of its posterior portions are likewise given 

 in the accompanying plates. Both specimens are of gigantic 

 size, one skull measuring five and one-half feet across the parie- 

 tal crest, and the other is nearly as large. They differ widely, 

 moreover, from the huge horned Dinosaurs hitherto found in 

 the same general horizon, and present characters in the skull 

 of much interest. 



In Torosaurus latus, the species first described, the skull 

 appears wedge-shaped when seen from above, as shown in 

 Plate II. The facial portion is very short and pointed, and 

 somewhat suilline in form. The nasal horn-core is compressed, 

 with a sharp apex directed forward. The frontal horn-cores 

 are large, and strongly inclined to the front, extending appar- 

 ently in advance of the nasal protuberance. The long, slender 

 squamosals diverge rapidly as they extend backward, their 

 outer margins being nearly on a line with the facial borders in 

 the maxillary region. . 



* This Journal (III), vol. xlii, p. 266, September, 1891. See also vol. xli, p. 167, 

 February, 1891. 



Am. Jour. Scl— Third Series, Vol. XLIII, No. 253.— January, 1892. 

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