ON BELMULLET WHALING S‘TATION. 175 
of the tail, running slightly downward and then horizontally forward, 
ended about 1 foot 3 inches behind the anus, and were here about 
7 inches apart. Generally these streaks run forward right up to the 
aus. 
No. 32, &, length 63 feet.—A very dark individual, although 
examined while quite fresh. The dark colour extended on the breast 
folds as well as in the furrows down to the mid-ventral line. 
No. 36, d, length 61 feet 6 inches.—This individual showed very 
clearly all the different kinds of light spots which are found on this 
animal. There are (a) narréw tadpole-shaped white spots, 1 inch to 
14 inch long; (6) small oval white spots, ¢ inch long; (c) large oval 
grey spots, with radiating dark lines,** about 24 inches by 1 inch at 
the broadest part; and (d) rings and patches of small grey spots: the 
rings are generally about 2 inches in diameter. These different kinds 
of spots are very variable in their intensity and distribution, and may 
be absent im some cases. 
The conclusion which must be drawn from these observations is 
that while variations in the intensity and distribution of the colour are 
yery common, yet in no case do the differences from the accepted type 
warrant the creation of even a sub-species. 
2. Balenoptera sibbaldii (Gray).—The colour of the four individuals 
examined by me did not show any great variation from the normal. 
‘They were of a bluish-black all over as the ground-colour, with light- 
grey fleckings and spots irregularly placed over the back. The grey 
fleckings were especially noticeable in the region of the umbilicus, 
extending up the sides. 
The breast folds from the front end to the level of the insertion of 
the pectorals was of the same colour as the back. Behind this there 
were more white marks placed irregularly on the folds and ridges. 
The whole of the upper jaw on both sides was of the uniform dark 
colour. The front inner part of the under jaw on both sides was a 
light-grey colour, with the dark colour in spots and fleckings. Both 
the plates and bristles of the baleen were black. The palate was also 
of the dark blue-black colour, not pink as in B. musculus. The 
yariations from this scheme were inconsiderable in the four individuals. 
No. 3°* had a patch of bright yellow on the breast folds, situated 
near the mid-ventral line, just behind the level of the insertion of the 
pectoral fins. The patch extended over about five ridges and was about 
5 feet long. e 
No. 4 was a lighter-coloured individual than usual. 
VII. Bopy Form. 
This was very constant both for Balenoptera musculus and for 
Balenoptera sibbaldii. It will be seen by reference to Tables VII. 
and X. that the dorsal fin of B. sibbaldii is relatively much smaller 
than that of B. musculus. In other proportions there is no very 
striking difference between the two species. 
Injuries in the form of large, irregular notches were fairly common 
35 Vide Collett, Proc Zool. Sor., 1886, p 249, pl. xxvi., fig. 2. (B. borealis). 
* Vide Table IIT. 
