TRICERATOPS HORRIDUS. 117 



Marsh, O. C, Am. Jour. Sci., 3d ser., vol. 3S, Aug., 1889. p. 174; vol. 38, Dec, 1889, pp. 501-506; vol. 39, Jan., 1890, pp. 

 81-83; vol. 39, May, 1890, pp. 418-426; vol. 40, Feb., 1891, pp. 168-177; vol. 40, Apr., 1891, pp. 339-342; vol. 42, 

 Aug., 1891, p. 181; vol. 42, Sept., 1891, pp. 265 and 266; vol. 43, Jan., 1892, pp. 82-84; vol. 44, Oct., 1892, pp. 343 and 

 346; Mar., 1894, p. 245; vol. 50, Nov., 1895, p. 412; vol. 50, Dec, 1895, pp. 485-498; 4th ser., vol. 6, July, 189S, 

 p. 92; Sixteenth Ann. Rept. U. S. Geol. Survey, 1896, pt. 1, pp. 145, 20S-214, 218, 227-228, 243; Mon. U. S. Geol. 

 Survey,' vol. 27, 1897, pp. 510-516. 



Nicholson and Lydekker, Manual Pal., 1889, vol. 2, p. 1163. 



Nopcsa, F. Baron, Foldtani Kozlony, Budapest, 1901, vol. 31, p. 271. 



Osborn, H. F., Bull. Am. Mus. Nat. Hist., vol. 5, 1893, p. 326; Science, new series, vol. 7, 1898, p. 844; Contr. Canadian 

 Pal., vol. 3, pt. 2, 1902, pp. 9, 20, 21. 



Steinman and Doderlein, Elements Pal., 1890, p. 665. 



Walcott, C. D., Science, new series, vol. 11, 1900, p. 22. 



Woodward, A. S., Outlines Vert. Pal., pp. 213, 216. 



Zittel, K. A. von, Text-book Pal., trans, by C. R. Eastman, vol. 2, p. 244. 



The type species of the present genus was founded on the greater portion of a skull (No. 

 1820, Yale Museum) from the Laramie of Converse County, Wyo. The genus is represented 

 by a number of species. All the representatives are of large size, and the skull is less fenestrated 

 than in any other genera. The genus may be characterized as follows: Supraorbital horns 

 directed forward and upward at an angle of 45° ; nasal horn of moderate length and directed nearly 

 straight forward; no parietal fontanelles; squamosal short and broad. 



Triceratops (Ceratops) horridus Marsh. 1889. 



Type consists of skull from the Laramie of Converse County, Wyo. (No. 1820, Yale Museum). 

 Original description in Am. Jour. Sci., vol. 37, Apr., 1S89, pp. 334-335. 

 Marsh, O. O, Am. Jour. Sci., vol. 38, Aug., 1889, p. 173, where it is made the type of the genus Triceratops. 



DISCOVERY. 



The type of the present genus and species consists of the greater portion of a skull (No. 

 1820, Yale Museum), with portions of the lower jaws. It is that from which the horn core 

 first seen by the present writer in the collection of Mr. C. A. Guernsey at Douglas, Wyo., was 

 taken. It is therefore of considerable historical importance as having led to the discovery 

 of that important locality in Converse County, Wyo., which has yielded so many and such 

 interesting remains of these and other Laramie dinosaurs, mammals, turtles, fishes, inverte- 

 brates, and plants. Unfortunately the skull was incomplete when found, a considerable por- 

 tion of it having already weathered away, and such portions as did remain are now separated 

 and preserved in two different collections. The major portion is in the Yale collection, while 

 the base of the right supraorbital horn core is in the private collection of Mr. C. A. Guernsey. 



This skull was discovered by Mr. E. B. Wilson, and was collected by the present writer. 

 It was found embedded in a hard calcareous sandstone concretion which had weathered out 

 of a stratum of soft, light, yellow, heavily bedded sandstone, about 20 feet thick, near the 

 middle of that series of fresh-water sandstones and shales which in this region are interposed 

 between the marine Fox Hills sandstones below and the leaf-bearing Fort Union beds above. 

 The locality is shown approximately at + 1 in PL LI. The exact location of this skull was 

 on the south side and about 5 feet above the bottom of the canyon which enters Buck Creek 

 from the west. It was about 100 yards above the springs now locally known as Hatchers 

 Springs, where Johnson Brothers' sheep ranch is now located. About 150 yards below and 

 on the north side of this canyon is a small "blow-out," or "badland area," about half an acre 

 in extent, situated just below the mouth of a small tributary from the north and directly 

 opposite the ranch buildings just referred to. From the same stratum of soft, light-colored 

 sandstone from which had weathered the concretion containing the skull found 150 } r ards 

 above, at this lower locality I obtained the type of Trachodon longiceps Marsh" and a consid- 

 erable number of isolated teeth of small Laramie mammals, as well as various remains of fishes, 

 reptiles, and amphibians. This mammal-bearing locality is shown at o 3 in PI. LI, while 



a Am. Jour. Sci., 4th ser., vol. 39, May, 1890, p. -122. 



