82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



large ]\L, though, does not appear to be relatively so wide as in 

 D. olseni. I suspect that Diacodexis olseni may be no more than a 

 variant of Diacodexis secans, whereas D. robustiis would appear to 

 be a distinctive species in Gray Bull time and may have continued on 

 into Lost Cabin time in the Washakie Basin. 



BUNOPHORUS, cf. MACROPTERNUS (Cope) 



(Plate 14, figures 6 and 8) 



An additional lower jaw of Bunophorus, cf. macropternus exhibit- 

 ing P3-P4 and M2-M3 (U.S.N.M. No. 22445) was encountered in 1959 

 in the Knight beds beneath the Fontenelle tongue in the upper part 

 of the Green River Basin. Also, an isolated M3 (No. 43823) in the 

 University of California collection from beneath the Tipton tongue 

 south of Dad, Wyo., may well represent the same species. The latter 

 is a little smaller than M3 in No. 19210 (pi. 14, fig. 8) or No. 22445 

 from near Big Piney tentatively referred to B. macropternus, but is 

 less worn. It shows no evidence of a paraconid. 



BUNOPHORUS, cf. ETSAGICUS (Cope) 



(Plate 14, figures 7 and 9) 



A lower jaw (U.S.N.M. No. 22244) with M1-M3 (pi. 14, fig. 9) 

 and an isolated M^, apparently belonging to a species of Bunophorus, 

 were found in the New Fork beds to the east and southeast of Big 

 Piney. Teeth in the lower jaw are only a little longer than those in 

 Bunophorus, cf. macropternus, from beneath the Fontenelle tongue, 

 but are much broader. They appear also to be possibly a little lower 

 cusped and with less evidence of a cingulum, in addition to a somewhat 

 more inflated appearance. 



The M^ (U.S.N.M. No. 22245 i pl- I4» %• 7), if correctly referred, 

 shows that upper teeth of the New Fork species were slightly larger 

 but with lower and more inflated-appearing cusps than the form 

 in the La Barge fauna. 



HEXACODUS PELODES Gazin 



(Plate 7, figure 2; plate 14, figures 1-4) 



Several more specimens of Hexacodus pelodes have been found in 

 the Knight exposures in the vicinity of Big Piney and La Barge, 

 and lower jaw portions that are referred to this species have also been 

 discovered in the New Fork beds (pi. 14, fig. 4). Moreover, a jaw 

 fragment with a single lower molar in the University of California 



