NO. I LOWER EOCENE MAMMALIAN FAUNAS GAZIN 1 5 



Hyracotherium, sp. ; and Hexacodus uintensis have been found at 

 the lower levels. 



Knight Station. — The localities along Bear River to the southeast 

 of Evanston and in the vicinity of Knight Station were discussed in 

 1952 and further exploration by Smithsonian Institution parties has 

 failed to uncover additional materials of new significance. Granger 

 (1914, p. 203) regarded these beds as equivalent to Lysite in age 

 and to date I find no reason to question seriously this conclusion. 

 Among the forms now recognized in the fauna from this locality 

 there may be listed the following : 



Cynodontomys, sp. Coryphodon radians (Cope) (etc.) 



Esthonyx, sp. Hyracotherium vasacciense (Cope) 



Paramys excavatus Loomis (incl. H. index) 



Hyopsodns hrowni Loomis Heptodon ventorwn (Cope) 



Phenacodiis priinacviis Cope Hexacodus pelodes Gazin 



Hexacodus uintensis Gazin 



Granger's conclusions were based on the presence of Heptodon, 

 which distinguished these beds from the Gray Bull level, and on the 

 species of Cynodontomys and Hyopsodns which he regarded as 

 nearest to Lysite forms of these genera. The Cynodontomys speci- 

 men may well represent C. latidens but the absence of premolars 

 leaves much to be desired. The Hyopsodns is of a size that strongly 

 suggests Lysite H. hrowni, but there is recent evidence to indicate 

 that a form of this size is present in the Dad fauna. Elsewhere this 

 has not been found in the La Barge horizon. The two species of 

 Hexacodus listed are based on the specimens listed by Van Houten 

 (1945, p. 458) from American Museum labels as Diacodexis, sp. 

 These had not been seen at the time of the 1952 report but have since 

 been found and their identity is discussed under the species of 

 Hexacodus. 



Identifiable remains of mammals are not frequently encountered in 

 the type section of the Knight, but of those found Coryphodon seems 

 most conspicuous, with Heptodon and Hyracotherium represented 

 by remains from more than one individual. The absence of Lamhdo- 

 therium, while entirely inconclusive, permits retention of a Lysite 

 assignment. 



Tipton Butte. — A locality near Tipton Butte that has produced a 

 number of isolated teeth was found by Roland W. Brown and George 

 N, Pipiringos in 1952. It is in the SW^ sec. 23, T. 20 N., R. 96 W., 

 near the top of the Red Desert member described by Pipiringos 

 (1955, p. 100). Recognized among the teeth are a small form of 

 Cynodontomys that may be C. angustidens; Pelycodusf, sp. ; Es- 



