694 
Proceedings of the Boyal Society of Edinburgh. [Sess. 
bone 37 mm. in transverse diameter, which was grooved for the flexor 
digitorum, and articulated with Mu on one side of the groove and with M m 
on the other, also with C T , centrale, intermedium and C 4 + 5 . Car- 
palia 4 + 5 formed a bone 42 mm. in transverse diameter, which articulated 
by its distal border with M IV and My ; opposite the interval between these 
metacarpals its distal and proximal borders and the dorsal surface were 
notched as if the two halves of the bone were imperfectly united, so that 
Fig. 1. — Riglit manus, palmar surface, Sowerby’s Whale, St Andrews. 
In this and other figures R means radius ; U, ulna ; r, radiale ; i, inter- 
medium ; u, ulnare ; c is a distal carpal, and the numeral associated with it is its 
number in the distal row ; C is os centrale ; the roman numerals are the meta- 
carpal bones ; P is pollex ; p is the pisiform element. 
it appeared that one part belonged to Mjy, the other to My ; it also 
articulated with C 3 , ulnare and the pisiform cartilage. Both in the 
St Andrews and 1885 animals the three distal carpalia represented the 
five distinct elements found in Hyperoodon, in which a distal carpal occurs 
for the metacarpal bone of each digit. It is likely that the two elements 
which formed the bone C 2 + 3 , as well as those of C 4 + 5 had, as in 
Hyperoodon, been developed independently in the carpal cartilage, but 
thereafter became conjoined. In the St Andrews animal a narrow bar of 
cartilage formed the ulnar border of the carpus and a nodule of bone, the 
