NOTES ON THE SALMO SALAR SPECIMEN — MORROW. 175 



10. The 10th short ray is nearly straight. Between ten and 

 eleven, attached to the upper edge of the 11th short fin-ray, at 

 about \\ inches from its inferior end is an extra bone ^ of an 

 inch in length. 



11. This ray is nearly straight, curving at its outer end to fol- 

 low the shape of the long rays ; it has a very thin pointed ven- 

 tral end ; its length is two and a half inches. 



The first short fin-ray is about ^ of an inch long. 



The eleventh short fin-ray is about two and a half inches long. 



The caudal fin has nineteen long or perfect rays (their inser- 

 tion in this specimen will average about one inch in length), which 

 begin to divide or split up into a great number of fin-rays, short- 

 ly after the exit of the tail from its root or body of the fish. The 

 first and second rays counting from the dorsal region are exactly 

 opposite to the centre of the elevation of the spinal column, so 

 that there are seventeen whole rays beneath it. 

 1 to 8. The first eight rays are closely united by strong fatty 

 tissue to their emergence from the integument. 

 S to 9. Between the inferior ends of eight and nine there is 

 a space of irregular outline filled with fatty tissue which ex- 

 tends some distance between these rays, at its widest part it 

 measures ^ of an inch. 



9 & 10. The inferior extremities of these rays meet for f of an 

 inch and are then separated for about § of an inch.* 



10 & 11. Are separated at their emergent ends. 

 11&12. do. do. do. 



The 9th, 10th, 11th & 12th rays are broader on their inserted 

 ends by cartilaginous matter, than are the other rays. 

 12 & 13. The inserted ends of 12 and 13 join for about a quar- 

 ter of an inch, but are then widely separate, and the ray thirteen 

 is inserted into the root of the tail an eighth of an inch more 

 than twelve. 



All the spaces enumerated above, beginning between eight 

 and nine and continuing to that between twelve and thirteen ex- 

 tend into the tail proper as a sort of web by which the tail may 

 be expanded and contracted in its width. 



* 10th ray. — A line drawn through the centre of the spinal column touches this raj 7 , the centre 

 Taj 7 of the caudal fin. 



