17£ 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-eights of an inch in length ; from the dor- 

 sal end of M 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 fin and its ap- 

 pendages.* 



1st intersp. fin bone, \ in length. ^ 



2 " " "1 " f these 3 bones anchylosed. 



3 " " " ljj " j 



4 intersp. fin bone, is 21J 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 2g inches lies between the points of 16 & 17 

 sp. rays, angle 40 degrees. 



6 intersp. fin bone 2\ between 17 & 18, angle 43 degrees. 

 ' 2s slightly in front of 19, angle 54 degrees. 



2 between 19 & 20, angle 55 degrees. 

 ' I| slightly in advance of 21, angle 55 degrees. 

 ( l! slightly in front of 22, angle 55 degrees. 



1? between 22 & 23, angle 56 degrees. 

 ' Is slightly in front of 24, angle 55 degrees. 

 ' It opposite the point of 24, angle 52 degrees. 

 ' 1| slightly in front of 25, angle 51 degrees. 



7 

 8 



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9 



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10 



ti tt 



11 



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12 



n a 



13 



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14 



ft u 



* This is much more apparent in the skeleton of the young Salmon. 



