706 
Proceedings of the Royal Society of Edinburgh. [Sess. 
shafts. The procarpus contained the three customary bones. The radiale, 
14 mm. in transverse diameter, articulated with radius, intermedium, the 
carpal cartilage associated with the pollex and with M n . The intermedium 
was 14 mm. wide, grooved on the palmar surface, and articulated with 
radius, ulna, radiale, ulnare and the two distal carpalia. The ulnare was 
7 mm. wide and articulated with ulna, intermedium, the more ulnar distal 
carpale, My, and with the pisiform cartilage. This cartilage was only 5 mm. 
wide and 7 mm. long, and extended from the ulnar epiphysis to Mv ; it did 
not contain an ossified nucleus. No os centrale was seen. 
Two distal-carpalia were situated in the mesocarpus. The more radial 
was a small bone 9 mm. wide, with a groove in line with that on the 
intermedium opposite the interval between Mn and Mm, with both of which 
the nodule articulated, as well as with the radiale, intermedium, and the 
more ulnar distal carpal. The last-named bone was 12 mm. wide, and 
articulated with ulnare, intermedium, the radial distal carpal, and M m , 
Mjy and My. The more radial bone apparently represented C 2 + 3 , and the 
more ulnar C 4 , or it may be C 4 + 5 . Both C T and C 5 were absent as 
independent units. 
The hand was pentadactylous. Digit I, the pollex, was so close to the 
radial border and so slender that it might easily have been overlooked. It 
was connected with a band of cartilage on the radial border of the carpus 
extending to the radiale, which, though no ossific nodule was found in it, 
might perhaps represent carpale Mi, 12 mm. long, was very slender, and 
had at its distal end an unossified phalanx. Digit II, the longest, consisted of 
M n , 21 mm. long, and six small osseous phalanges, the terminal of which was 
no bigger than a very small shot ; it was connected with the carpal cartilage 
of the pollex, the radiale, and the outermost distal carpal. Digit III had a 
metacarpal 20 mm. long and five small phalanges ; M m articulated with both 
distal carpals. Digit IV had a metacarpal 13 mm. long and three small 
phalanges. Digit V projected from the ulnar side of the carpus ; My, 8 mm. 
long and 11 mm. wide, was connected with Miy, the ulnar distal carpal, the 
ulnare and the pisiform cartilage. 
The presence of three bones in the procarpus of the porpoise and of only 
two disto-carpalia has been generally described by anatomists. Both 
Weber and Kiikenthal numbered them as C x and C 2 . Ktikenthal con- 
sidered that C l5 as described in this memoir on the radial border of the 
carpus, was either absent or blended with Mi, or with the radiale ; 
his C Y would therefore represent my C 2 -fC 3 conjoined, whilst his C 2 
might be the conjoined C 4 + C 5 , though more likely from its position only 
C 4 , whilst C 5 had either not developed or had blended with the ulnare. 
