164 NOTES ON THE SALMO SALAR SPECIMEN—MORROW. 
bases, and towards the anterior dorsal edge of 55 the bony plate 
nearly touches 54. 
55, 56,57. Are anchylosed, and on 57 is the last dorsal spinous 
ray proper; but in addition, and anchylosed with the three 
spinous rays above named, are two or three other rays, which 
may be termed representative. J 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 spmous ceén- 
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 55 degrees. 
Saddle bones. 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 no‘ochord, 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 3 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 candal fin- 
rays, right and left side, have a slight attachment. 
