164 NOTES ON THE SALMO SALAR SPECIMEN — MORROW. 



bases, and towards the anterior dorsal edge of 55 the boDy plate 

 nearly touches 54. 



55, 56, 57. Are anehylosed, and on 57 is the last dorsal spinous 

 ray proper ; but in addition, and anehylosed with the three 

 spinous rays above named, are two or three other rays, which 

 may be termed representative. I cannot decide their number 

 they are so confused. These three rays unite with a short bone, 

 which is attached to the 57th sp. ray, and lies nearly parallel 

 with the 57th and 58th spinous centra. The 57th spinous cen- 

 trum begins to rise, that is, to curve upwards towards the dorsal 

 edge of the caudal fin, and with the 58th and 59th centra and 

 the lower Y shaped bone between the forks of which the noto- 

 chord passes, forms an angle with the anterior part of the spinal 

 column of about 35 degrees. 



Saddle hones. Beginning at the posterior edge of the 56th cen- 

 trum are a pair of bones of irregular and peculiar shape, one on 

 each side of the spine. They are attached to the dorsal edge of 

 the spine, and are joined by strong cartilage in this specimen, by 

 their ventral anterior edges to the posterior edge of the 56th cen- 

 trum, covering the ventral end of the 57th sp. ray, anteriorly 

 about \ of an inch, nearly at the middle of its height ; their dor- 

 sal edges pass over the 57th sp. ray, posteriorly they cover and 

 attach the three rays which do not reach the spinous centra, 58 

 and 59. These bones, which, for lack of a better name, I will 

 call saddle bones, attach the three rays which I have already 

 spoken of as representative rays, by cartilaginous union to the 

 spinal column. When these bones are in their proper position 

 the spinous rays appear to be all perfect; but the 58th and 59th 

 centra have no dorsal spinous rays. Close to the posterior end 

 of these saddle bones, protecting the notochord, and lying 

 under the anterior edge of the short caudal fin ray, No. 10, 

 reaching nearly to the dorsal edge of the spinous centra, is on 

 each side a short irregularly shaped bone, about | of an inch in 

 length, somewhat pointed at either end. On the outer sides of 

 the posterior extremities of these two short bones, the points of 

 the short caudal rays next to the first perfect dorsal caudal fin 

 rays, right and left side, have a slight attachment. 



