16 THE CERATOPSIA 



Locality 15 (Fig. 2) is situated south of the Seminole Mountains, on the west side of the 

 North Platte River, about one mile from that stream, and 40 miles below Fort Steele. Here, in 

 1888, Hatcher found considerable ceratopsian material consisting of parts of the skull, vertebrae, ribs, 

 and other portions of the skeleton, all in such fragmentary and decomposed condition as to render 

 their determination impossible. In the same general locality, from the Medicine Bow formation of 

 the Hanna Basin, Carbon County, there have been found bones belonging to the ceratopsians but not 

 sufficiently diagnostic for generic determination. This formation is best exposed along both sides 

 of the North Platte River, at the mouth of the Medicine Bow River. 



In the Ferris formation of the Hanna Basin, there were obtained "indeterminable fragments of 

 ceratopsians, and a few specimens that have been identified by C. W. Gilmore as Trkeratops." 

 The formation "is best exposed from the old Ferris ranch, on North Platte River, eastward to the 

 top of the hill north of 'Middle Ditch' at its junction with 'Big Ditch'." 8 



Locality 16 (Fig. 2) is in Sweetwater County in southwestern Wyoming, not far from Black 

 Buttes station on the Union Pacific Railroad. It was here, in 1 872, that F. B. Meek discovered the 

 type of Agathaumas sylvestris (No. 4000 A.M.N.H.) which consists of about 16 vertebrae, the 

 sacrum, the right ilium, and fragments of ribs. 



COLORADO 



Locality 17 (Fig. 2) is on Green Mountain Creek, near Denver. It was here that George L. 

 Cannon found a pair of supraorbital horn cores in 1887, first described by Marsh as Bison altkornis, 

 but later referred to Ceratops and finally to Trkeratops altkornis, type, No. 4739 U.S.N. M. From 

 the same general locality, near Brighton, Messrs. Cross and Eldridge collected a considerable num- 

 ber of fragmentary dinosaur bones No. 1871, No. 6530 U.S.N. M. There was also a nasal horn core 

 described by Marsh as the type of Trkeratops galeus, No. 2410 U.S.N. M. 



In 1931, a U. S. Geological Survey party collected what is probably ceratopsian material from 

 the Dawson arkose, east side Section 9, Township 14 S., Range 62 W. (Loc. 18, Fig. 2). 



NEW MEXICO 



New Mexico has given us some of the most recent finds. Locality 19 (Fig. 2) is in San Juan 

 County. The following material has been discovered there: 



Pentaceratops sp., No. 12,002 U.S.N.M., a left squamosal, found by G. F. Sternberg in 1929, in 

 the southwest quarter section, Township 24, Range 1 3 W. 



Ceratops (?), No. 8604 U.S.N. M., the median bar of a fenestrated ceratopsian dinosaur, collected by 

 Reeside and Clark, ?>y 2 miles southwest of Kimbetoh, near the south side of Section 4, Town- 

 ship 22 N., Range 10 W., in the Kirtland formation. 



Ceratops (?), Considerable portion of a right squamosal, collected in the southeast corner of Sec- 

 tion 4, Township 22 N., Range 1 W., in the Kirtland formation. 



Monoclonius (?), No. 5798 A.M.N.H., part of a supraorbital horn; and small sections of charac- 

 teristic squamosal bones, not collected. From the Ojo Alamo sandstone. 



Monoclonius (?), No. 7347 U.S.N. M., coossified atlas, axis, third and fourth cervical vertebrae, con- 

 siderable portions of several dorsal and caudal vertebrae, parts of two pubes, and fragments 

 of other bones, collected in the Fruitland formation in Amarillo Canyon, 1 miles south of San 

 Juan River, and 2 l / 2 miles east of Chaco River. 



Monoclonius (?), No. 8359 U.S.N.M., proximal portion of an ischium, found in the uppermost 

 part of the Kirtland shale, about 4 miles west of Farmington, 34 mile east of Mesa Point, and 

 1 mile south of San Juan River. 



8 Bowen, C. F., 1918, p. 230. 



