Vol. 4] Furlong. — Preptoceras, a New Ungulate. 



165 



From the associated fauna and the occurrence of the deposit, 

 Preptoceras is considered to be of Quaternary age, but prob- 

 ably somewhat later than the epoch represented by the principal 

 deposit at Potter Creek Cave. 



Cranium. — The cranium is that of an immature individual 

 in which the last permanent teeth are being erupted. It is 

 slightly larger and more robust than the skull of Euceratherium. 

 Viewed from the front there is a strong resemblance to Budorcas 

 taxicola, and like the latter there is a suggestion of affinity with 

 the Musk Ox. The horn-cores of Preptoceras differ from those 

 of Budorcas and Ovibos in length and curvature. In both of 

 these characters they closely resemble those of Bos. 



The nasals and frontals are partly destroyed in the type 

 specimen, but in another individual from the same deposit they 

 are complete. The nasals are flat dorsally with steeply sloping 

 sides. The anterior ends are decurved and converge to form a 

 blunt point. Posteriorly, the ends slope upward to the fronto- 

 nasal suture. The posterior ends are not separated to form two 

 distinct points as in Budorcas. 



The frontals rise from the nasals at a steep angle and are 

 much inflated dorso-ventrally above the orbits. In Eucerather- 

 ium the frontals, while slightly convex above the orbits, do not 

 rise from the nasals at a sharp angle, but present rather a plane 

 with uniform inclination from the nasals to the base of the horns. 



The horn-cores grow from the extreme posterior and lateral 

 ends of the frontals, and show distinct burrs at the base. They 

 are situated rather wide apart at the base. The cancellous tissue 

 extends but a short distance above the burrs. In the proximal 

 two-thirds the anterior surface is flattened, and the posterior 

 surface strongly convex. The distal third is rounded and tapers 

 gradually. In Euceratherium the horn-cores are much closer to- 

 gether at the base, and in size and curvature suggest those of 

 Capra. 



The parietals and frontals are fused just back of the horns, 

 the parietals forming the dorso-posterior roof of the cranium. 

 The parietals slope posteriorly at a sharp angle to the promi- 

 nent lambdoidal crest. 



