712 
Proceedings of the Koyal Society of Edinburgh. [Sess. 
so that at a later stage only four cartilaginous distal carpalia were present. 
A fusion of carpale 3 with C 4 might also occur and the number be reduced 
to three carpalia, C 1? C 2 , C 3 + 4 . He thought that carpale 5 probably 
became a part of the ulnare. He saw sometimes two centralia, one of 
which might remain, though usually both fused with adjoining bones. 
In an important memoir on the Anatomy of a Beluga the late Sir John 
Struthers gave a detailed account with figures * of the structure of the 
manus. The procarpus consisted of the three customary bones, whilst the 
other bones were regarded as four distal carpalia C Y to C 4 , a small os centrale, 
and a pisiform, the ulnare, centrale, C 3 and pisiform not being ossified. 
As Sir John Struthers had presented to me for the Anatomical Museum this 
and other specimens from his collection of cetacea, I have examined the 
manus, and I concur in his interpretation of the carpal elements. Thus 
carpale Y belonged to the pollex : C 2 was mainly for M n , though with a 
slight articulation with M m : C 3 was for M m , though C 4 was divided 
equally between Mm and M IV and its distal angle intervened between these 
two metacar pals : no independent C 5 existed, for My articulated directly with 
the ulnare, which was relatively large and probably included, though still 
in the cartilaginous stage, C 5 , and its dorsal angle also reached the base of 
M IV . The area of cartilage interposed between radiale, intermedium, C x and 
C 2 , which Struthers regarded as an os centrale, holds the position of that 
carpal element and may be regarded as its unossified representative. The 
formula of this carpus corresponds with No. 4 of the formulae of Beluga given 
by Klikenthal on p. 28 of his memoir, except that there is only one os centrale. 
Min. 
Ann. 
Med. 
hid. 
Pollex. 
Ph 3 
Ph 3 
Ph 4 
P'v, 
1 
Ph 4 
I 
rly 
Miv 
Mm 
M n 
i 
Mi 
pis. 
<v"’ 
k 
P2 
k 
cart, 
ulnare 
Cen. 
intermedium radiale 
Ulna Radius 
Mgnodon mongceros {Narwhal). 
In 1887 and 1889 Professor Leboucq of Ghent published an account of 
his researches on the morphology of the hand in marine mammals; f and 
described the constitution of the carpus in four foetuses of the Narwhal. 
* Journ. Anat. and Phys ., vol. xxx., Oct. 1895. 
t Anatomischer Anzeiger , 16th March 1887 ; Archives de Biologie , t. ix. p. 571, 1889. 
