464 THE WASATCH FAUNA. 



The size of this species precludes the possibility of its identity with 

 any of the other species described here. 



The Big-Horn Basin, Wyoming; J. L. "Wortman. 



Phenacodus voetmani Cope. 



Bulletin U. S. Geol. Surv. Terrs., F. V. Hayden, \j, 1881, p. 199; Paleontological Bnlletin, No. 34, 

 1882, 179, Feb. 20. Eyracotherium vortmani Cope, American Naturalist, 1880, p. 747. Phenacodua 

 apternxis Cope, Paleontological Bulletin, No. 34, pp. 179, 180. 



Plates LVIIjr, LVIIA, LVIII; figs. 8-10. 



This was a rather abundant species in Wyoming during the Wasatch 

 Epoch. The best specimen in my possession is a nearly perfect skeleton 

 found by Mr. J. L. Wortman near the Big-Horn River in Northern Wyo- 

 ming. This I now describe. 



Cranium. — Pressure has distorted the skull so that the superior surface 

 is oblique to the sides, and the frontal region is a little crushed in. By 

 viewing the two sides, however, a fair idea of the general form may be at- 

 tained. The premaxillaries are not so produced as in the P. primcBVus, and 

 they unite on the middle line at their extremity in a Gothic arch. The free 

 portion of the nasal' bones is short, is somewhat contracted, and is obtuse 

 at the extremity. The profile is probably nearly straight. The orbit is of 

 moderate size, and extends as far forwards as above the first superior true 

 molar. The facial plate of the maxillary bone is uniformly gently concave. 

 The sagittal crest is well developed, of medium height, and commences at a 

 point one-third way between the posterior border of the orbit and the supra- 

 occipital crest. The latter is bilobate, moderately notched on the middle 

 line, and the alee have not much transverse extent. It continues into the 

 zygoma as the posterior temporal crest, and sends a distinct branch down- 

 wards to near the extremity of the posttympano-paroccipital process. There 

 is a small lachrymal tuberosity on the anterior edge of the orbit. The 

 supraorbital border is rather thick, and terminates in a distinct short an- 

 gular postorbital process, which is directed downwards. The zygomatic 

 arch is not stout nor convex The orbital edge of the molar is a little 

 flared outwards, and it supports no trace of postorbital angle. The post- 

 glenoid process is prominent, is rather broad, with a convex inferior mar- 

 gin. The meatus auditorius is widely open below. The posttympanic and 



