166 NOTES ON THE SALMO SALAR SPECIMEN—MORROW. 
very short spinous processes lying in front of their articulation 
with their centrum. 
0. 28. The 26th pair of ribs have spinous processes about } of an 
inch in length, to which they are attached and pass pasate 
to their articulation. 
C.29. The 27th pair are united by cartilage to the end of, and 
behind spinous processes $ an inch in length on the 29th centrum, 
their ends do net reach the centrum but are attached posteriorly 
to the sp. processes. This pair are not so flat as their preceding 
ribs 
C. 30. The 28th pair. The spinous processes to which this pair 
are attached are 3 ef an inch in length, and their attachment 
rather more than a quater of an inch. 
C. df, The 29th pair are attached posteriorly to strong sp. pro- 
cesses 2 of an inch in leneth, which are united canoer aie form- 
ing the first heemal arch. 
C. 32. The 30th pair. Their spinous processes are also about 2 of 
an mene in length to which the attachment of the ribs is about 
3, of an inch, 
(, 93. 31st pair of ribs ) have sp. processes 3 and % of an inch 
C.34. 32nd do. Jin length, and have short attachments 
to their processes. 
C. 35. On this centrum, (the last of the abdominal centra), at- 
tached to spinous processes, which are united at their ventral 
ends, are the 33rd and last pair of ribs. A hasty examination of 
this specimen might lead one to say that it has only 32 pairs of 
ribs ; but the dorsal ends of the 33rd pair are attached closely 
together and to the narrow point of their sp. processes, and are 
anchylosed. The examination of younger fish makes this cer- 
tain. This pair of united ribs forms the support of the anterior 
interspinous fin bone of the anal fin, which in this case it over- 
lapped, and was attached on the right hand side about 3 of an 
inch.* 
The ventral ends of the last five or six pairs of ribs gradually 
approach each other until they touch in the last or 33rd pair, 
> 
* The sp. processes of the 29th, to and including the 83rd and last pair of ribs, are transversely 
united, making five abdominal hemal arches, 
