ON THE OSTEOLOGY OF RISSO's GRAMPUS. 
415 
SEVEN DORSAL VERTEBRA. 
From the thoracic vertebrae there are seven to the motor axis 
of spine, which I have reckoned as dorsal vertebrae, as here the 
spine is nearly perpendicular, the general inclination of the spines 
being towards it on both sides. 
FOURTEEN LUMBAR VERTEBRAE. 
The next fourteen vertebrae having no inferior chevron, I have 
considered lumbar. 
TWENTY-SEVEN CAUDAL VERTEBRAE. 
The first nineteen of the remaining vertebrae have haemal 
chevrons attached to the inferior surfaces of the intervertebral 
discs by cartilage. The depth of these commences at an inch and 
two lines, gradually increases to two inches and nine lines at the 
fourth, continues about the same to the ninth, when it gradually 
diminishes to the last, which is only three lines high. 
These chevrons, with their spines, nearly reproduce in shape the 
neural arch and spine on the vertebrae above them. 
At the seventh caudal vertebra their bodies begin to get more 
massive, and deeper than wide; and at the twelfth the lateral 
processes are almost obliterated. 
The six caudal vertebrae are perforated in the body on each side, 
just above the lateral processes. These perforations, which are 
repeated in all the vertebrae to the end of the tail, approach more 
and more to the top of the body, till, in the eighteenth and to the 
last, they are quite on the upper surface, on each side of the spine 
or centre. The bodies of the vertebrae are compressed laterally 
to the eighteenth, which is nearly cylindrical, from which to the 
last they are compressed horizontally. 
LENGTH OF NEURAL SPINES. 
The neural spines are very short at the neck ; their measure- 
ments will be given from above the neural arch : 
in. lines. 
Spine of cervical vertebrae (points backwards) . .13 
First thoracic (vertical) . . ..09 
Second „ (points forward) . . ..09 
Third „ „ . . ..09 
Fourth „ (points backward) . . .10 
