4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 



deciduous series and the number of vertebrae in the sacrum is con- 

 sistent with M eniscotherium. 



Later reports of discovery and description of new materials include 

 an announcement by Granger in 1910 of the finding of Menisco- 

 therium in the Lost Cabin beds of the Wind River Basin. He 

 regarded this as the first record outside of the Wasatchian of New 

 Mexico, although in 1915 he noted materials collected from the Wind 

 River Basin as early as 1896. He was evidently not aware of the 

 listing of M eniscotherium chamense by Clarence King in 1878 in 

 the fauna for his Vermilion Creek group in Wyoming. The faunal 

 lists in King's work, according to Hay (Bibliography of 1902), were 

 probably furnished by Marsh, and it follows that the material referred 

 to may well have been the Knight skull collected for Marsh in 1875 

 and that much later became the type of M eniscotherium robustum 

 Thorpe. In 1915 Granger reviewed the characters and distribution 

 of the genus M eniscotherium, revising the species to include Cope's 

 M. terraerabrae as a subspecies of M. chamense, and adding the 

 new species Meniscotherium( ?) priscum from the Clark Fork Paleo- 

 cene of northwestern Wyoming. Regarding it as a second species 

 of Paleocene age, Russell (1929) described M eniscotherium semicin- 

 gulatum from a locality in Alberta, Canada. The age is questioned 

 but thought to be Clark forkian because of the association of Ptilodus 

 with forms of Wasatchian aspect. 



It was not until 1934 that the material of M eniscotherium referred 

 to above as having come from southwestern Wyoming in 1875 was 

 described. Though rather poorly preserved, the specimen includes 

 most of the skull and lower jaws. It was collected for Marsh by 

 William Cleburne in a railroad cut near Aspen in Uinta County. 

 Thorpe made this the type of the new species M eniscotherium robus- 

 tum, a form that I (1952) found to be characteristic of the La Barge 

 fauna from the Knight beds in the Green River Basin. In this 1934 

 paper Thorpe also gave the evidence for suppressing Marsh's name 

 "Hyracops," which in any case had long been regarded as a synonym 

 of M eniscotherium. 



The known distribution of M eniscotherium both geographically 

 and geologically was summarized by Van Houten in 1945, and certain 

 suggestions as to its ecology were presented by Simpson in 1948 as 

 a part of his discussion of the occurrence of M eniscotherium in the 

 San Jose beds of New Mexico. In a study of the Knight faunas of 

 southwestern Wyoming in 1952 I summarized briefly the history of 

 M eniscotherium discoveries and called attention to the abundant, 



