NO. 8 MAMMALIAN FAUNA, BADWATER AREA — GAZIN 3I 



medius. One of the jaw portions (U.S.N.M. No. 21 104) with P4 and 

 Ml falls within the size range of the Myton material, but the other 

 (U.S.N.M. No. 21 103), which has P3-M1, is a little larger than any 

 in the above series. Nevertheless the latter is closer in size of teeth 

 to L. medius than it is to L. proavus. The structure of the lower pre- 

 molars in these jaws corresponds very closely to that regarded as 

 characterizing Lcptotraguhis. 



The teeth in both Nos. 21 103 and 21 104 are significantly smaller 

 than in the type of Leptotragiilus? significans Russell from the Kish- 

 enehn beds in British Columbia. Although I have not examined 

 the Kishenehn specimen, from Russell's clear description and stereo- 

 scopic illustrations I would favor referring his form to Lepfomeryx 

 rather than Lcptotragulus. As a consequence, there would seem to be 

 somewhat better evidence for the Oligocene age postulated by Russell 

 as an alternate possibility for the Canadian occurrence. 



LEPTOREODON?, sp. 



Plate 3, figure 3 



A couple of isolated premolars in the collection, a little smaller than 

 in Leptoreodon marshi but not greatly diflferent in size from Lepto- 

 traguhis medius, exhibit a well-defined metaconid. In one of these 

 the metaconid is opposite the protoconid and shows a well-defined 

 groove between them anteriorly, much as in characteristic material 

 of Leptoreodon. The parastylid, however, is a well-developed column 

 distinct from the anterior crest of the protoconid, suggestive of 

 Lepfomeryx. Nevertheless, as in Leptoreodon and unlike Leptomeryx, 

 the talonid basin is formed by the posteroexternal crest swinging 

 lingually near its posterior extremity, joined only by a weak spur 

 from the metaconid. In Leptomeryx, the hypoconid and entoconid 

 in P4 are in most cases sharply separated and join forward with the 

 protoconid and metaconid respectively. The second isolated P4 ex- 

 hibits a parastylid much as in Leptotragulus, but the metaconid, 

 though weak, is distinct and unlike Leptotragulus. This tooth has a 

 very primitive look and may not represent any known leptotragulids. 



REFERENCES 



Burke, John J. 



1934. Mytonolagus, a new leporine genus from the Uinta Eocene series in 

 Utah. Ann. Carnegie Mus., vol. 23, pp. 399-420, pi. 50. 

 Clark, John. 



1939. Miacis gracilis, a new carnivore from the Uinta Eocene. Ann. Car- 

 negie Mus., vol. 27, pp. 349-370, figs. 1-2, pis. 34-37- 



