1891-92.] Prof. Sir Wm. Turner on the Lesser Rorqual. 
63 
thoracic artery almost immediately arose. The cord of the ductus 
arteriosus connected the commencement of the left pulmonary artery 
with the arch of the aorta almost opposite the origin of the left sub- 
clavian. 
The Skeleton . — As the bones of the Granton Balsenoptera were 
fully ossified, and as the animal had attained its adult proportions, 
some general observations which I have made on the skeleton may 
be referred to. It is not, however, necessary to write a description 
of the individual bones, as Eschricht, Van Beneden, Gervais, 
Flower, and other cetologists have already entered with considerable 
detail into the subject. 
The vertebral formula was C^D^^^L^gCd^g = 50. In order to 
obtain a correct determination of the number of caudal vertebrge, 
regarding which observers have differed materially in their state- 
ments, the terminal caudals were carefully dissected in situ.^ when 
ten vertebrae were counted between the two flanges of the tail, and 
in front of the flanges nine vertebrae bore chevron bones. The 
terminal caudal was a nodule of bone OG inch (11 mm.) broad and 
0*27 inch. (7 mm.) in antero-posterior diameter : a circular con- 
striction differentiated it from the vertebra immediately anterior 
to it, with which it was fused. The distance between the last 
caudal and the free edge of the median notch of the tail was half an 
inch (13 mm.). The penultimate vertebra was 0*86 inch (22 mm.) 
broad by 0‘7 inch (18 mm.) in antero-posterior diameter. The 
third vertebra from the tip of the tail was 1‘45 inch (37 mm.) 
broad by 1*2 inch (30 mm.) in antero-posterior diameter. Had the 
tail been macerated, the two terminal caudals would in all proba- 
bility have been lost, and the vertebral formula would then have 
read = 48, which is the usual number ascribed to B. 
rostrata^ although some observers have given only 46 or 47 
vertebrae in this species. Professor Flower counted 50 vertebra 
in the male, 24 feet 4 inches long, stranded at Overstrand, near 
Cromer, in November I860,* a number corresponding to that in the 
Granton specimen, and which, doubtless, expresses the correct 
* Proc. Zool. Soc., May 24, 1864, in which the follomng formula is given, 
C 7 ,Dii,Li 2 ,Cd 2 o = 50. This skeleton is in the Museum of the Royal College of 
Surgeons of England, hut in Professor Flower’s catalogue of the collection the 
formula is modified as follows, C 7 ,Dji,Li 2 ,Cdjg = 49. 
