of Edinburgh, Session 1881-82. 
451 
Oulodon ; but Reinhardt’s observation, as he himself has pointed 
out, shows that this can no longer be regarded as a ground for 
generic distinction between it and Mesoplodon. 
In writing the description of the other bones of the skeleton, I 
have followed the method which I pursued, in framing the account 
of the skeleton of the Mesoplodon layardi for the Reports of H.M.S. 
“ Challenger,” so that the skeletons of these two animals may now 
be compared with each other. But it must be remembered that 
Bayard’s Mesoplodon , though 14 feet in length, was an immature 
animal, whilst the Shetland Sowerby’s whale of the same length was 
an adult male. 
Spinal Column. — Only 39 vertebrae have as yet reached me, 
viz., Cf, D 10 , L n , and eleven caudals. In the Brussels skeleton 
there are 46 vertebrae, and the formula is C 7 , D l0 , L 10 , Cd 19 . In 
Professor Malm’s specimen, which was adult, as the epiphyses were 
united with the vertebral bodies, the formula is C 7 , D 10 , L 9 , Cd 20 = 46 ; 
and in the second Goteborg skeleton, obtained by Dr. A. H. Malm, 
there are also 46 vertebrae, but of these only 9 are dorsal vertebrae, 
and consequently there are only 9 pairs of ribs. The ribs, there- 
fore, of this whale are either 9 or 10 pairs, and the vertebral for- 
mula is 46, so that seven caudal vertebrae are missing in my speci- 
men. In Bayard’s Mesoplodon the vertebral formula is 44 or 46, 
and the ribs are either 9 or 10 pairs. 
The length of the macerated spine — the vertebral bodies being 
placed in apposition — was 9 feet 1 1 inches. The discs varied from 
half to five-eighths of an inch in thickness, so that 20 inches in 
addition may be allowed for them, and about 8 inches for the 
missing vertebrae with their discs, which would make the spine a 
little more than 12 feet long. In the centre of each disc was a dis- 
tinct and relatively large cavity, lined by a smooth synovial-like 
membrane, and containing a deep yellow fluid, which in the discs 
between the larger vertebrae might amount to about half an ounce. 
The arrangement resembled what I saw in 1869 in the discs of 
Balcenoptera sibbaldii. 
Cervical Vertebrae. — The antero-posterior diameter of the cervical 
series of vertebrae was 5J inches. The body, laminae, and spine of 
the axis were completely fused with the corresponding parts of the 
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