NOTES ON THE SALMO SALAR SPECIMEN—MORROW. Loe 
has a wide articulating surface on its inner side or heel for its 
union with the radius upon which it moves, this surface is fur- 
nished with the usual lining and ligaments of such joints ; from its 
inner to outer heel transversely it is in breadth j of an inch. 
Outer side of the pectoral fin—The heel of the first or upper 
ray is $ of an inch in length, and nearly at right angles to its shaft, 
the heel inclining away from its supporting bone, and at the 
same time turned towards the ventral aspect of the fish. 
The heels of the remaining rays gradually increase their angles 
or have less abrupt curves until the last two or three rays, 
when their curves again become sharper, the lengths of all de- 
ereasing, but the outer heel of the lowest or short ray preserves 
nearly the normal shape, and projects an ; of an inch below the 
supporting ossicle. On its inner side the heel of the long ray is 
very stout, and its edge inclining downwards gives it a broad 
termination for the accommodation of the articular joint. The 
heels of the next six rays gradually decrease in their length and 
curves until the Sth ray is nearly straight; the 9th, 10th, 11th, 
12th and 13th rays are also nearly straight, but closely crowded 
together, and the inner heel of the 14th is curved upward and al- 
most overlaps the end of No. 13; the outer heel of 14 is, from out- 
side to outside, } of an inch below the inner extremity. All the 
rays are on each side attached to the basé of the fin, 
by strong cartilage, which fills the division of or the space 
between the rays, so much so that without destroying the fin, 
which at present cannot be spared, it is impossible for me to give 
a more particular description of it. 
At the junction of the clavicles, which are connected by carti- 
lage and closely attached to their united ends by strong fatty 
tissue, is the urohyal bone, in this specimen it is 1} inches in 
length, and { of an inch in height at its posterior extremity; at 
this point begins its ventral transverse plate, for half an inch of 
its length it is very narrow, but it rapidly widens until it 
attains 3 of an inch, taking a lanciolate form. This bone is per- 
pendicular to the body of the fish, and by its anterior end it is 
attached to the hyoid bones. 
This brings us now to the head of the fish on the ventral 
