476 THE WASATCH FAUNA. 



Measurements of scapvla. 



M. 

 Totallength 106 



Diameters of glenoid cavity ^^"^'''•''P'''*''™'" "^^ 



c transverse 012 



Width of neck 0-30 



Elevation or spine at acromion - Oil 



Length of coracoid from internal base 004 



The humerus is relatively somewhat more slender than that of P. pri- 

 mcBVUs. In its details it is much like that of that species, but differs in the 

 following points : The head is rounded in outline, or not compressed as it 

 is in some degree in P. primcevus. The subscapularis fossa is much less ex- 

 tended anteroposteriorly, and is more oblique. The bicipital and epitroch- 

 lear ridges are less prominent, and the epitrochlear bridge is rather longer. 

 The three characters do not differ from those of P. primoevus. The tuberos- 

 ities are well developed, though not produced as in most Diplarthra. The 

 proximal external edge of the greater tuberosity forms a convex ridge. The 

 anterior boundary of the smooth surface of the head becomes a ridge on the 

 inner half, and ends in a low angular tuberosity in the fundus of the bicip- 

 ital groove. The fossa teris minoris is large and impressed. The crista 

 teris major is weak proximally, but becomes prominent at the proximal 

 third of the shaft. It is continued downwards on the front of the shaft as 

 the rather obtuse angular anterior edge. It is less prominent than in P. 

 primcBVUs and Periptychus rhabdodon, and less evidently continuous with the 

 deltoid crest than in many ungulates. The epicondyles are not very 

 prominent, but the internal is the most so. The epicondylar foramen is 

 rather larger than in P. primcevus. The condyles are not much extended 

 transversely. There is considerable trochlear surface on the distal external 

 side of the flange, and terminates in a fossa posteriorly. The roller is quite 

 convex, and the posterior trochlear groove is wide, deep, and somewhat ob- 

 lique. 



The ulna is stouter than the radius to near the distal extremities, where 

 the long diameters are equal. The carpal extremity of the ulna is of course 

 the most contracted. The ulna is however not so robust that the radius 

 appears to cross it as in the Proboscidea, but it is compressed so as to be 

 deep. The inferior edge is an angle, except at the extremity of the olec- 

 ranon, and has a gently convex profile to about the middle of the length 



