434 THE WASATCH ErOCH. 



Phenacodus nuniencs Cope. 



Plate LVIIh; figs. 1--2. 



The largest species is represented by humeri and parts of a scapulae 

 of two individuals, and probably by other bones, which were found mingled 

 together with the bones of a P. primcevus and a Mesomjx ossifragus in great 

 confusion. Tiiese bones can be compared with those of P. primcevus, and 

 several differences besides the superior dimensions appear. 



The glenoid cavity of the scapula is longer anteroposteriorly and nar- 

 rower transversely than in P. primcevus. The proximal part of the spine 

 rises nearly half way between the anterior and posterior borders of the 

 neck ; in P. primcevus it is much nearer the posterior edge of the neck. The 

 head of the humerus is more nearly rounded and less extended obliquely 

 forwards and outwards than in P. primcevus. The tuberosities are less 

 prominent, and the greater has a more obtuse extremity in the P. nunienus. 

 The subscapularis facet on the inner side of the lesser tuberosity is more 

 distinctly defined, forming a well-marked groove running upwards and for- 

 wards. The deltoid crest extends down the shaft, and is represented b}- an 

 angle as far as the fossa for the head of the radius. Tlie epicondyles are 

 not prominent ; the inner is the most so, and is marked by the arterial fora- 

 men. The bridge inclosing this is quite narrow. The condyles have a thin- 

 edged flange on each side posteriorly. Anteriorly the external disappears, 

 and the internal becomes beveled so as not to be acute. 



Measurements. 



M. 



Total length of humcrua '245 



Width at proximal extremity 066 



Anteroposterior diameter of head 044 



Widtli of humerus distally 065 



Width of condyles in front 040 



Width of condyles posteriorly O'Z! 



Median diameter of condyles O'ii 



Diameters proximal end scapula 5 anteroposterior 05i 



( transverse o:tl 



Length of glenoid cavity 040 



Width of neck 049 



Several posterior feet accompany the bones, some of which are clearly 

 those of P. prim<svus. The calcanea are all of the same size. Some have 

 larger runoiforin bones, and the navicular loss produced pnsteriorlv, while 



