um.

The proximal end of the ulna is similar to that of the radius but is
slightly larger. Posteriorly, there is a short, broad expansion
resembling the entepicondyle of the humerus, and even more nearly like
the postaxial flanges in a crossopterygian fin.

The ends of the radiale are expanded and rounded, the entire bone being
approximately twice as long as wide. The three sides of the intermedium
are similarly convex. The surface of this bone is unfinished, showing
that it must have been embedded in cartilage. The ulnare is
conspicuously similar to the ulna in bearing a posterior hooklike
expansion, and is larger than the radiale.

The four metacarpals are slightly expanded proximally and distally.
Although measurements of length and width are tabulated below (Table
2), we are not certain of the sequence of these bones in the row.

The dimensions of the two proximal phalanges are alike. The shape of
these elements is similar to that of the metacarpals. The two terminal
phalanges are somewhat triangular in shape, the lateral edges being
concave and the proximal convex.

TABLE 2.--APPROXIMATE MEASUREMENTS OF THE FORELIMB (in mm.)

--------------------------+-------------------------------------------
| Dimensions
+----------+--------------------------------
ELEMENT | | Width
| Length +----------+----------+----------
| | Proximal | Midway | Distal
--------------------------+----------+----------+----------+----------
Humerus | 16.0 | 5.0 | 2.0 | 7.5?
Radius | 9.0 | 4.0 | 1.5 | 3.5
Ulna | 8.5 | 4.5 | 1.5 | 3.5
Radiale | 3.0 | 2.0 | 1.5 | 2.0
Intermedium | 1.5 | -- | 2.0 | --
Ulnare | 3.5 | 2.0 | 2.0 | 2.5
Metacarpal A | 4.5 | 2.5 | 1.0 | 2.0
Metacarpal B | 4.5 | 3.0? | 1.5 | 2.5
Metacarpal C | 4.0 | 2.0 | 1.5 | 2.0
Metacarpal D | 3.5 | 2.5 | 1.0 | 1.5
Proximal Phalanx A | 2.0 | 1.5 | 1.0 | 1.5
Proximal Phalanx B | 2.0 | 1.5 | 1.0 | 1.5
Terminal Phalanx A