224 TOE WASATCH AND BRIDGER FAUNiB. 



the advance copies of which bear date August 7, 1872. This is also the 

 day of pubhcation of the paper in which the name Tomitherium rostratum 

 was proposed. Professor Marsh's description is extremely brief, consisting 

 of five lines and six measurements. No fuller description from Professor 

 Marsh's pen has appeared since. An elaboi*ate description of my own speci- 

 mens appeared May 6, 1873, in a paper entitled "On the Primitive Types 

 of the Orders of the Mammalia Educabilia," which was included in the 

 Proceedings of the American Philosophical Society for that year. My 

 original description was fuller than that of Professor Marsh, consisting of 

 seventeen lines and seven measurements. 



PP:LYC0DUS Cope. 



Systematic Catalogue of the Vertebrata of the Eocene of New Mexico, Explorations and Surveys west 

 of 100th Meridian, G. M. Wheeler, 1875, p. 13. 



Having received considerable accessions to my material, representing 

 species which I have referred to this genus, I am of the opinion that the 

 latter is distinct from Tomitherium, with which I formerly united it. The 

 character on which I originally proposed it, the two-rooted second pre- 

 molar, is constantly present in several species. I may add that the third 

 trochanter of the femur in Tomitherium has the elevated position seen in 

 Lemtcridoe, while in Pelycodus it has the position on the middle of the shaft, 

 as in the Creodonta. 



The superior molars of Pelycodus tutus have the following characters : 

 First, one-rooted ; second, two-rooted ; third, three-rooted. Crown of 

 fourth transverse, with one external cusp, with base antero-posteriorly 

 extended, and one internal cusp. The true molars possess two exterior 

 cusps which are flat on the external face. The first and second have two 

 internal cusps, and the third has but one. Of the inferior molars, the last 

 has a well-developed heel. The anterior inner cusps of one or more of the 

 molai"s are double. Tiie fourth premolar has an internal tubercle and a 

 heel. The third has no internal tubercle. The heels of the true molars 

 are not bounded by elevated cusps behind. I have pointed out in my 

 report to Captain Wheeler that the tibio-tarsal articulation in this genus is, 

 like that of most of the Creodonta, without trochlea. 



