Cope.] 582 [Feb. kj, 



The displaced metacarpal is flattened, and expanded at the extremities. 

 One side is nearly flat, but slightly concave in the longitudinal direction; 

 the other side is convex and nearly level in the longitudinal direction. 

 The lateral borders of the shaft are thus narrowed. The distal end displays 

 a convex condyle, and a flat, prominent ala, which is in the general plane. 

 The ala is separated from the condyle by a deep groove on the convex side. 

 The condyle is a half-hemisphere only, presenting only with the convex 

 side of the shaft, from which it is not separated by a constriction. It is 

 bounded at its distal edge by an angle, which is a continuation of the 

 proximabedge of the ala. The proximal extremity is injured at one angle, 

 but, with this complete, would be nearly a regular rhomboid with parallel 

 longer and shorter outlines ; the acute angle of the latter being the con- 

 tinuation of the lateral border of the shaft. The extremity is subtruncate, 

 and part of. the surface is irregularly excavated by pits and grooves. The 

 transverse extent of the proximal end, when perfect, was probably a little 

 greater than that of the distal. 



The two adjacent metacarpals are subequal in length, and longer than the 

 displaced one by one-fourth the length of the latter. One of these bones is 

 throughout rather thicker than the other, although the transverse diameter 

 of the shafts is equal ; but the stouter bone is considerably more dilated at 

 the extremities. The distal end of the stouter bone is thickened in the 

 direction at right angles to the plane of the limb ; but the chief expansion 

 is in that plane. The angle next to the other bone is protuberant, while 

 the other angle is expanded into a sharp, convex crest, or ala. A section 

 of this extremity is diamond-shaped, with one of the lateral planes pro- 

 duced into this crest, while the corresponding border of the opposite side 

 drops down, being represented by a mere convexity of the surface which 

 continues to the crest. The surface of the extremity is irregular. The 

 section of the shaft is a broad oval, becoming subcircular near the proximal 

 extremity. The latter is enlarged in both directions. It is a rectangle in 

 outline, a little extended in tlie plane of the limb, with one of the angles 

 cut off" from the corresponding angle to the middle of one side. The long 

 side thus left is slightly convex, and ends in an angle. The side subtended 

 by this angle is slightly concave, and is approximated to the other bone. 

 The opposite side is slightly emarginate near the middle. Its surface is 

 very slightly convex, and is irregularly grooved and pitted. 



The more slender of the two bones is but little and about equally ex- 

 panded at the opposite extremities. The distal end would have an ovoid 

 section, but for the fact that it is obliquely truncate at the extremity next 

 to the other bone. It is convex in the antero posterior direction and plane 

 in the transverse ; its surface is grooved and pitted. The side next to the 

 other bone is flat or slightly concave at the distal end, and, though thicker 

 than the external b&rder, becomes rounded at the middle of the shaft, and 

 is again flattened at the proximal extremity. The external border is dis- 

 tally produced into an obtuse angle ; lower down, the shaft has a thin, 

 angular border. The proximal end has less antero-posterior diameter than 



