172 NOTES ON THE SALMO SALAR SPECIMEN—MORROW. 
Dorsal Fin. 
The dorsal spinous rays make an angle with the spinal column 
(speaking generally) of from 35. to 42 degrees, and the first inter- 
spinous fin-bone of the dorsal fin consists of three bones anchy- 
losed, appearing at the articulation of the dorsal fin ray as one 
bone expanding into three. The anterior edge of these bones has 
a somewhat broad face, three-sixteenths of an inch at its widest 
part, and it is seven-eighths of an inch in length; from the dor- 
sal end of 4 interspinous bone, springs a very strong fibrous 
attachment, embracing the inserted ends of the triple intersp. 
fin bone ; it then passes downward and is strongly attached to the 
end of the 4th intersp. fin bone, (counting the short bones above 
mentioned, as three), which is the first long intersp. fin bone of 
the dorsal fin. This bone is slightly in front of the 16th spinous 
ray, which has no extra interspinous bone. The 16th sp. ray is 
a little less in length than 15, and from it, to and including the 
25th ray, a gradual curve is formed by the extremities of the 
dorsal spinous rays for the insertion of the dorsal tin and its ap- 
pendages.* | 
Ist intersp. fin bone, { in length. 
2 s See ge | . these 3 bones anchylosed. 
3 ae oa a aelie 4 
4 intersp. fin bones, is 2 \} inches in length, and forms an angle 
of 42 degrees with the vertebral column, while the sp. ray (16) to 
which it is opposite makes an angle of 35 degrees. 
5 intersp. fin bone 23 inches lies between the points of 16 & 17 
sp. rays, angle 40 degrees. 
6 intersp. fin bone 2: between 17 & 18, angle 43 degrees. 
the Ae “«  « 23 slightly in front of 19, angle 54 degrees. 
Sur ans “« « 2 between 19 & 20, angle 55 degrees. 
Or ge “ « 13 slightly in advance of 21, angle 55 degrees. 
10)... “ “ slightly in front, of 22, angle 55 degrees. 
i oe « «Ii between 22 & 23, angle 56 degrees. 
A Diap se « « 13 slightly in front of 24, angle 55 degrees. 
13 “  “ 4% opposite the point of 24, angle 52 degrees. 
DA « lj slightly in front of 25, angle 51 degrees. 
«This is much more apparent in the skeleton of the young Salmon. 
