TRANSACTIONS OF SECTION D. 533 
fangs are rough and truncated, the crowns of two worn down at the sides for some 
distance ; this looks as if the teeth were used for crushing. These teeth are not 
perfectly straight; two are slightly S-shaped. The smallest teeth are 2 cm. in 
length. In the lot I examined there are six; of these, four have small diameters, 
and two are wide and short, with thick fangs and a tendency to form two or three 
roots in one case. A small hole is present in the crown of the broadest and 
shortest tooth, but in the other short ones it does not appear. In another select 
group 2'2 em. is the height. The crowns are not worn down enough to show the 
cavity ; one of the teeth is bulged out at the lower part of the fang, as if a new 
root were attempted. One of the next group shows the central foramen in the 
crown distinctly, and two others imperfectly. The lengths are 13cm. Another 
group, six in number, have a length of 2°5 cms.; none are perforate above. The 
sockets for the individual teeth appear at the bottom of the groove; the 
partitions do not reach the upper edge of the jaw. The lower jaw is 45 cms. 
long, with a height of 11 cms. behind condyle. The condyle is 4 cms. from lower 
border, and 5 cms. from upper edge. There are 25 sockets on each side in upper 
jaw, and 20 on each side in lower jaw. The antero-posterior of the left nasal 
is more than half the corresponding diameter of the right. The length of the 
skull is 21 inches, breadth 10 inches, and height 21 cms. The right premaxilla 
41 cms., left 385 cms. The lower border of nares to the tip of the rostrum 
36 cms. The skull is less symmetrical than that of Delphinapterus, and the 
shape is intermediate between that of Delphis Delphinapterus and Grampus. 
Professor Anthony has found stones in the second stomach of Phocena. The 
green stuff sometimes found in the stomach of Tursiops may be accidentally 
swallowed with shore fish. 
TaBie.—Length of Teeth. 
6teeth . a ‘ 2 2- omss—. 3 3 . 1 tooth 2-4 cms. 
3teeth . 3 < . 22cms. . i ‘i . 3 teeth 2-5 cms. 
6teeth . fA 7 . 23cms. . 5 : . 1 tooth 3-4 cms.! 
ltooth . 3 ‘ . 2:35 cms. . F c . 1 tooth 3-5 cms.? 
1 tooth 4-1 cms.? 
Two of the short teeth are broad; one of these has a broad fang imperfectly 
divided. 
6. Some Notes on the Skeletal Elements of the Mammalian Limb. 
By Professor R. J. ANpERSoN, M.D., F.L.S. 
The condition of the elements of the mammalian limb is commonly associated 
with that of other vertebrate groups that have a manus and pes developed. It 
is easier to explain the structure of the fish limbs by referring to the archetype 
skeleton than to explain the structure of other vertebrate types in this way. 
The wings of birds may be referred, however, to a modified variety of the 
archetype skeleton. Whatever views we adopt, it can scarcely be advisable to 
undervalue the main factors in the production of the foci of relative rest and in 
the maintenance of periodic activity. These are as much in evidence in fishes 
and more easily understood than in the higher vertebrates. If specimens of 
wood are cut so as to form long, thin, and moderately wide bars, and if 
Lycopodium spores be shaken over the surfaces of these boards, tapping can be 
made to produce vibrations that will throw the powder into nodes and internodes 
not unlike the skeletal parts of the vertebrate limb. Muscle thrills associated 
with movement and neuro-muscular actions become consciously or unconsciously 
associated with aspirations of the central or other neurones. It seems clear that 
the limbs of selachians, sea lizards, and cetacea give us favourable illustrations 
of the results of the primitive attempts of movement by limbs and fins. Birds 
are somewhat removed from the accomplishments of these groups, but the 
feathers represent facts that accomplish for the wings and tail similar results in 
a medium where local vortices are made to help in the locomotion. Mammals 
* Cut down at side for 0.6 cm. 2? Cut down at side for 1 cm. 
* Bevelled at crown. 
