480 M. R, Thorpe — Neiv Fossil Carnivora. 



No. 6903, A. M. N. H., consists of the anterior half of a 

 skull with rami, about the size of Taxidea americana. 

 The muzzle is short and stout, lacking the constriction 

 anterior to P^, common to the Canid<©. The zygomatic 

 fossa is short ; the orbits small, and the infra-orbital fora- 

 men above the interval between P^ and P^. 



The rami are robust, with deep masseteric fossae. The 

 condyles are on a line with Mj, while the coronoid is 

 wide and high. The canine is stout, and the premolars 

 short and massive. P^ is very small; P^ but slightly 

 ovate ; P^ somewhat obliquely placed ; P^ large, with a 

 well developed deuterocone, and the blades separated by 

 a distinct notch. Matthew says of M^ (p. 193) that it 

 **is reduced antero-posteriorly and much extended trans- 

 versely, the paracone nearly median, metacone vestigial 

 and parastyle much extended, protocone compressed, and, 

 as in all primitive Mustelines, it lacks the broad flange 

 characteristic of the modern Mustelidse. ' ^ M- is small 

 and oval. 



The inferior premolars are slightly spaced and Pj is 

 very diminutive. M^ has a rather large heel and a well 

 developed metaconid, while M2 is small and oval, with 

 the meta- and hypoconid of nearly equal height. 



Oligohums darhyi, sp. nov. 



(Figs. 4, 5.) 



Holotype, Cat. No. 10272, Y. P. M. Skull and jaws. Lower Miocene 

 (Monroe Creek beds — lower Harrison), Pine Eidge, 12 miles north of Har- 

 rison, Sioux Co., Nebraska, on the Warbonnet ranch, in Sec. 2, T 32 N., E 

 56 W. Collected in 1914 by Mr. Fred Darby, after whom the species is 

 named. 



Specific characters. — The skull is approximately the 

 same size as that of Icticyon venaticus, the South Amer- 

 ican bush dog (Groldman 1920, p. 149), or considerably 

 smaller than that of 0. crassivultus. It is strongly doli- 

 chocephalic, with a very short muzzle. There is a large 

 infra-orbital foramen above the posterior margin of P^, 

 the superior contour slopes gently both ways from the 

 junction of the temporal ridges, the length of the zygo- 

 matic fossa is equivalent to about one third of the total 

 skull length, the sagittal crest is barely marked, and the 

 zygomatic arches are very slender. 



The cranial and basicranial areas of this genus have 

 been unknown heretofore. The bullas are partly broken 



