Chapter 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 ·154
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 forward, and decreases in size as it approaches the distal end. The proximal end has its articular face for the humerus divided into three facets, the vertical being long and extremely convex; the horizontal has the pre-axial face the longer. The olecranon is very massive and rugose, sending up on its external side a high, pointed projection; while on the internal side, the olecranon becomes compressed and projects inward; these tuberosities are separated by a wide, shallow groove for the tendon. The distal articular face is large, single, and is concave antero-posteriorly, and convex laterally. The styloid process is very heavy.

_Measurements of Ulna._