MR. W. H. FLOWER ON THE OSTEOLOGY OF THE SPERM-WHALE. 361 
radiale, intermedium, and ulnare of Gegenbauer. ‘The middle one is usually the 
largest and most thoroughly ossified. In the genus Orca alone there is no ossification, 
even in the adult animal, corresponding to the cuneiform. 
4. The three bones of the distal row are generally represented by distinct ossifica- 
tions in Hyperoodon, Beluga, and Monodon. These appear to correspond with the 
trapezoid, magnum, and unciform of human anatomy. 
5. In most cases the bones of the distal row of the carpus are reduced to two, which 
appear to correspond best with the trapezoid and unciform, the magnum being either 
absent or amalgamated with the trapezoid. I here differ from Dr. Van Bambeke, who 
considers that the two bones of the distal row represent the magnum and the trape- 
zoid, the unciform being absent. My reasons are :— 
a, The magnum in mammals generally is a smaller and less important bone than the 
unciform, 
6. In those animals in which the carpus approaches most nearly to that of the Cetacea 
in configuration and functions, but retains all its elements distinct, as the Manatee, the 
magnum and the trapezoid are particularly reduced, while the unciform is large, and 
occupies the position of one of the well-developed bones of the cetacean carpus. 
¢, In those Cetaceans in which all the bones of the second row are developed, and 
can be distinctly recognized, as in Hyperoodon, the magnum is small. 
d. In the skeleton of a Beluga I have found the magnum present, while in the 
carpus of another animal of the same species, otherwise completely ossified, its place 
was occupied by cartilage. 
e. Whenever the magnum is present as a distinct bone, it is placed exactly above 
the middle of the third metacarpal bone, and has a carpal bone on each side of it, 
articulating with the second and fourth metacarpals respectively. In the Cetacea having 
but two bones in the second row of the carpus, the middle of the proximal end of the 
third metacarpal corresponds with the interval between these bones, which articulate 
respectively chiefly with the second and fourth metacarpals, each taking a portion of the 
third. Sometimes this interval is so large as to suggest the absence of a bone. 
f. It is, however, not improbable that the bone which in general position corresponds 
with the trapezoid, as it forms the chief support to the second metacarpal, may also 
contain the representative of the magnum. ‘This seems clearly to be the case in the 
carpus of Micropteron sowerbyense, according to a sketch kindly sent me by Professor 
Yan Beneden, in which a single, transversely elongated bone corresponds to the bases 
of both the second and third metacarpals. This view is also confirmed by the extremely 
reduced condition of the trapezoid in the Manatee. 
6. The trapezium appears never to be present as a distinct bone, although the first 
metacarpal so often assumes the characters and position of a carpal bone that it may 
easily be taken for it. The rudimentary and simple character of the bones of the manus 
of the Cetacea is well illustrated by the difficulty of interpreting the nature of the 
