

77 



Basal width of distal end of spine -030 



Basal width of middle part of spine -on 



Length of glenoid cavity 149 



Width of glenoid cavity -096 



The Huinerus (Plate VII., Fig. i). The humerus is 

 short, but excessively stout, twisted slightly on its axis ; it 

 decreases gradually in size downward, with the smallest 

 diameter about two inches below the end of the deltoid 

 ridge. The head is large, hemispherical, and sessile, pro- 

 jecting very slightly out of the axis of its shaft. The great 

 tuberosity is heavy, but not high, and is separated from the 

 low lesser tuberosity by a shallow bicipital groove. 



The trochleas are very nearly equal in size, directed ob- 

 liquely to the axis of the shaft, and are separated by a narrow 

 groove, which runs from the supra-trochlear fossa down and 

 in, then back and up to the anconeal fossa. The condylar tu- 

 berosities are large and rugose ; the external is the greater, and 

 is directed antero-posteriorly. The deltoid ridge is long and 

 heavy, and extends nearly two thirds down the shaft, branch- 

 ing out into two forks near its end. The supinator ridge is 

 short and rudimentary, differing in this respect entirely from 

 the great development found on the humerus of the Probos- 

 cidea. 



The supra-condylar fossa is small, sub-circular in form, and 

 very deep, it has the peculiarity of being placed above the 

 external condyle alone. The anconeal fossa is median in 

 position and quite deep. 



Measurements of Humerus. 



M. 



Length -63 



Smallest circumference of shaft just below deltoid ridge -288 



Greatest proximal circumference below greater tuberosities -45 



Width of trochlea on anterior side !54 



Length of anconeal fossa -071 



Width of anconeal fossa -062 



Width of distal end at condylar tuberosities -23 



Length of deltoid ridge 22 



Length of groove running from supra-trochlear to anconeal fossa -272 



The Ulna (Plate VII., Fig. 2). The ulna is long, heavy 

 at both ends, with a slender trihedral shaft that curves for- 

 ward, and decreases in size as it approaches the distal end. 



