40 
TICirriAllY VJiliTJiliRATA OF TILE FAYtjM. 
luiir at tlic back. I'lic i)roximal surface for tlic cuneiform [cii.) is concave antero- 
postciiorly and convex from side to side. Distally the bone bears two large surfaces 
I'or tlic fourth and fifth metacarpals, and a much smaller inner surface for the outer 
facet of the slightly displaced third metacarpal. The surface for the fourth 
metacarpal is somewhat concave and looks directly downwards ; that for the fifth is 
convex and looks downwards and outwards, almost joining that for the cuneiform 
externally, making with it the acute angle which is the thin edge of the wedge. 
'I'he bone is deeper posteriorly than anteriorly. 
d'hc metacarpals (text-fig. 10, ]x 4 0) were short and stout and much enlarged at their 
articulations. The first is unknown, but, judging from the size of the distal articulation 
of the scaphoid, probably little reduction had taken place on this side of the foot. 
Text-fig. 24. 
Left unciform of Arshwlther'nnn zitteli : A, from above ; B, from below; C, inner (preaxial) face. 
cu., facet for cuneiform ; «no/., facet foi' magnum ; me. 3, 'me. 4, me. facets for the tliird, 
foarlli, and fifth metacarpals. 4 nat. size. 
The second is likewise unknown, but it had on its postaxial side a small surface for 
articulation with the magnum, as is shown by the presence of the corres])onding facet 
on that bone. The third articulated mainly with the magnum, but had a slight 
overlap on the vneiform at least anteriorly. The fourtli and fifth articulated with 
the unciform, and in some cases [e. g., C. 7968) the fifth seems also to have iiad a 
surface of contact with the cuneiform (text-fig. 25, cu.). The ])osterior free of the 
upper end of the metacarpals seems in all cases to be ])roduccd backwards into a 
strong roughened prominence. 
