ShuI'KI.dt : OsTEOi.oov OK riiK IIkkodionks. 11)<J 



For its length ami the general size of the bird, the shaft of the 

 radius is ijuite slender. In form it is subtrihedral with the salient 

 angles rounded off. 



Usually the ulna is quite straight, or has only a slight degree of 

 curvature, but in the present subject it is bowed nearly as much as 

 the radius and very much in the same way. It is hardly necessary 

 to say that in common with the radius and the skeleton of the pinion, 

 that it is likewise found to be a perfectly non-pneumatic bone. Its 

 shaft is about two and a half time^ the size pf the radius, l)ut instead 

 of being subtrihedral in form, it is nearly cylindrical. 



Two rows of quill-knobs are distinctly seen upon its length, one on 

 the ulnar and one on the palmar aspect ; the former being the more 

 strongly marked. 



The shaft decreases in size gradually from the proximal to the dis- 

 tal end, very imperceptibly from the middle of the bone on. A 

 nutrient foramen is seen on the anconal aspect at the proximal part 

 of the middle third. 



The carpal end shows the usual trochlear surface, and the facets 

 for the raJiale and ulnarc of the wrist. Proximally, the enlargement 

 is much greater in order to afford sufficient breadth, to make room 

 for the extensive excavations that are found at this end, to articulate 

 with the radius and bone of the brachium. The olecranon is but 

 feebly developed and tuberous. Measurements taken from these 

 bones in an adult specimen of Ardea heiodias, shows the humerus to 

 be 19 cm. long; the radius 22 and the ulna 23.1, which goes to 

 show that the brachium and anti-brachium are proportionately bal- 

 anced as to their respective lengths. Both of the carpal elements 

 are present, the radialc and the iilnare. They are of good size, 

 articulate as in most birds, and are fashioned after the most usual pat- 

 tern assumed by these bonelets. 



The carpo-inctacar[)tis makes up in length in this heron what it 

 otherwise lacks in breadth. It measures 10.3 cm. long, while across 

 the widest part above it is but 1.8 cm.; this latter measurement being 

 from superior tip of jjollex metacarpal directly across the bone to outer 

 edge of trochlear surface. 



The first metacarpal, anchylosed as usual at the upper and anterior 

 aspect of the bone, is very short, slightly bent anconad, and directed 

 rather upwards as a tuberous process. Beneath, it supports the exten- 

 sive convex articular facet for pollex digit, which latter is long and 



