162 NOTES ON SALMO SALAE SPECIMEN — MORROW. 



Art. VII. — Notes on the Bones of Salmo Salar Specimen 

 from Labrador. By R. Morrow. 



Read April 19th and May 10th, 1880. 



Spinous Rays, <&c. Beginning at the junction of the dorsal 

 ridge with the occiput there is a bony process in advance of the 

 first spinous ray ; flattened vertically, somewhat broader above, 

 but stouter below, it is attached to the dorsal region by stout 

 fibrous tissue, its ventral extremity at about midway to the 1st 

 spinous ray, and it is the first interspinous bone;* it is entirely 

 different in form, from its representative in the ubiquitous perch, 

 and were it cut out and looked at merely as a fish bone, few 

 would recognize it as an interspinous bone, from the description 

 of such bones as usually given. 



2 & 3. The 2nd & 3rd spinous rays have each a short interspin- 

 ous bone attached to their extremities, overlapping posteriorly. 

 ]/.. This ray is without the intersp. bone.-f- 



5. The 5th spinous ray has its interspinous bone overlapping in 

 front, and rather longer than those belonging to 2 & 3. 

 6 — 15. All these sp. rays have their intersp. bones overlapping 

 anteriorly, but the loth spinous ray curves posteriorly rather 

 more than Nos. 12, 13 & 14, and at the loth sp. ray there is an 

 extra interspinous bone £ (making 2 bones i il) which does not 

 reach, but its end is opposite the front of the loth spinous ray, 

 distant about one quarter of an inch from it ; it does not rise so 

 high in the dorsal region as the other interspinous bones, say \ 

 of an inch less than « (f 4 lies immediately behind & from which 

 it is distant about \ an inch) ; u and the preceding intersp. bones 

 are nearly equidistant from each other ; « is very nearly a 

 straight bone, tapering slightly from its dorsal to its ventral ex- 

 tremity. The dorsal ends of the 14 interspinous bones have 

 somewhat broad beads} for the attachment of the muscular tissue, 

 and all are curved anteriorly, 



16. This spinous ray is without an intersp. bone, but the 

 4th intersp. fin bone of the dorsal is slightly in front of it. 



* In younger specimens this 1st intersp. bone has almost always its ventral extremity lying 

 between the superior extremities of the 1st spinous ray ; as this raj' becomes more solid, the 

 intersp bone seems to be pushed out. 



t In a fish from Cape Breton the 4th has an interspinous bone, but the 5th is without. 



\ More perceptible in smaller specimens. 



