l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



thonyx bisulcatus; Paramys, cf. excavatus; Vulpavus, possibly V. 

 asms; Hyopsodus, sp. ; Menisc other ium cf. robustum; and Hyraco- 

 therium. I earlier reported these to Pipiringos as being about equiva- 

 lent to Lysite or Lost Cabin in age. I believe now, however, that the 

 age is probably not as late as Lost Cabin. It may well be Lysitian or 

 late Graybullian, but the evidence is not critical. 



La Barge. — The outstanding occurrence or series of localities in the 

 Knight member is that for the La Barge fauna in the vicinity of 

 La Barge and Big Piney, essentially all in Sublette County. As 

 described in 1952, the horizon of the Knight involved is exposed 

 principally in the various canyons or draws on both sides of the 

 Green River between La Barge and Big Piney and to a point about 

 12 miles north of Big Piney. Fossil remains were encountered from 

 a few feet to more than a hundred feet below the Tipton (Fontenelle 

 of Donovan) tongue of the Green River. Certain of the more profit- 

 able localities in these beds have been revisited on various occasions 

 in later years, particularly that on Muddy Creek near where it is 

 crossed by the highway north from Big Piney. 



Most of the 1952 report was devoted to the La Barge fauna, and 

 the evidence relating to its Lostcabinian age considered in detail 

 (1952, pp. 10-12). The significance of the occurrence of the species 

 M eniscotherium robustum discussed then has since been modified by 

 various scattered finds in the northern part of the Fossil Basin, and 

 new information on the fauna is afforded by recognition in it of such 

 genera as Palaeictops, Apatemys, Omomys, Chlororhysis, Knightomys, 

 and Dawsonomys not cited in the earlier list. The number of genera 

 of mammals now identified in the fauna is 31, representing about 40 

 species, out of an entire number of about 53 genera and approximately 

 95 species considered in this report for the lower Eocene portion of the 

 Wasatch. This total number does not include early Knight occurrences 

 in Colorado described by McKenna. 



Dad. — A long escarpment of Knight exposures beneath the Tipton 

 tongue on the east side of the Washakie Basin, well known to col- 

 lectors in the Wyoming region, extends along the west side of Muddy 

 Creek and highway U.S. 330 from near Dad P. O. southward, inter- 

 rupted by several long canyons heading to the west, to the vicinity of 

 Baggs. While specimens have been found in many scattered locali- 

 ties, most of the material collected by the Smithsonian Institution, 

 Carnegie Museum, and University of California parties has been 

 from the large promontory-like exposures near Dad. Hyracotherium 

 is particularly common in this area. 



