207 
Phalanx IIT., 1, is distingnished by the height and breadth of 
its proximal, and the breadth and depression of its distal, 
end. The contour of the proximal articulation, of which the two 
principal diameters are nearly equal, is shown in PI. v,, fig. 5 
IT. Generally a low vertical elevation, present only in the in- 
ferior half, indicates a partial division into two facets, of which 
the inner is rather the larger. From the superior and inferior 
borders of this surface the upper and under surfaces of the shaft 
incline towards one another, the inclination being greater in the 
latter. In the middle of the bone the section is a transversely 
elongated oval, which becomes more flattened towards the distal 
end. On the under surface, a little in advance of the articular 
border, are two rough elevations which leave a shallow trough 
between them. The distal expansion is almost of the same 
lateral width as the proximal, but between the two ends the shaft 
is considerably narrower. The distal articular surface forms a 
trochlea, of which the convexity in a vertical direction exceeds a 
semicircle. A shallow median groove which extends in the same 
direction throughout its whole extent divides it into two convexi- 
ties of about equal lateral width, though, in vertical depth, the 
inner considerably exceeds the outer. The lateral surfaces of 
the distal expansion are occupied by depressions, of which the 
inner is the larger. 
Phalanx ITT., 2, approximates to a quadrangular contour when 
viewed from above, the Jength, however, being somewhat greater 
than the breadth. Its proximal articular surface is ovoidal, with 
the larger end internal. A very slightly marked vertical rising 
obscurely indicates a division into two facets, both of which 
are concave vertically. Of these, the inner facet is slightly the 
larger. The shaft is very greatly depressed, the lateral diameter, 
just posterior to the distal expansion, being to the vertical as 31 
mm.to9mm. The distal expansion itself is also characterised 
by great breadth and small vertical height ; its articular surface, 
which extends further back below than above, forms a trochlea, 
the groove separating the two convexities being very broad and 
shallow, and the inner moiety slightly the deeper in a vertical 
direction. A shallow depression for the lateral ligament exists 
on the outer side of the distal expansion, but it is only feebly 
indicated on the inner. There may be one or more nutrient 
foramina on the under surface. 
Phalanx ITI. 3 is considerably broader than long, in the pro- 
portion of 34 mm. to 18 mm., and much depressed. The proxi- 
mal articulation is reniform with the convexity superior and, 
owing to a slight posterior production of the superior and inferior | 
borders, particularly of the latter, this surface is concave verti- 
cally and mesially, but nearly flat on each side. The anterior 
O 
