1891 - 92 .] Prof. Sir Wm. Turner on the Lesser Borqual. 67 
ten without chevrons were included between the flanges of the tail. 
The greater number of these vertebras were keeled on the ventral 
surface of the body, and the keel was grooved antero-posteriorly, so 
as to be divided into two ridges, which possessed in the vertebrae 
associated with chevron bones distinct areas for their articulation. 
The eight anterior caudals possessed laminae and spines enclosing a 
neural canal, they diminished in magnitude from before backwards. 
Transverse processes were present in the five anterior caudals, but 
in the 5th the process was diminished to a slight ridge. In the 
4th and 5th the transverse process was perforated, where it sprang 
from the side of the body, by a vertical foramen. The height of 
the 1st caudal vertebrae was 19 inches, its breadth was 17 inches ; the 
vertical diameter of the body was 7 inches, its transverse diameter 
was 8 inches. 
Nine chevron bones were present, the eight anterior of which 
consisted of a pair of haemal arches with a haemal spine ; but the 
9th was only ossified in its left half, and was not more than 1 inch 
in antero-posterior diameter. Except the last chevron, the others 
had separated from the caudals, and it seemed as if that which 
articulated with the 2nd caudal was the largest of the series ; it 
measured 9 inches in height and 6f inches in its greatest antero- 
posterior diameter. In the natural skeleton of Knox’s specimen the 
3rd chevron was the longest. They diminished in size from it in 
one direction to the 1st, which was very small, and in the other to 
the last, which was also very small. 
It is unnecessary to give a description of the Skull of B. rostrata, 
as it has been described and figured by several writers on this 
species. It may, however, for purposes of comparison, and as the 
crania are from animals of different ages, be useful to arrange in a 
tabular form some of the principal measurements of the series of 
crania nowin the Anatomical Museum of the University (Table II.). 
Both Knox’s specimen and that caught at Alloa are quite young. 
If we take the length of the adult animal as 28 to 30 feet, and that 
of Knox’s specimen as 10 feet, the latter had attained about one- 
third its growth, and was probably not more than a few weeks 
old. 
In removing the lower jaw of the Granton specimen, it was 
observed that the great fibrous pad which connected the condyle of 
