17 
1914-15.] The Baleen Whales of the South Atlantic. 
cutis, when its deep surface showed the rich black rete Malpighi, which 
contrasted with the pink cutis. The dorsal fin and the dorsal mesial ridge 
were greyish black, but the dorsum of the tad was quite black. The 
dorsum of the beak was dark grey, which was modified to light grey at 
the border of the beak, the upper lip and around the orbit. 
On the sides of the body the cuticle was translucent and colourless, and 
the vascular cutis subjacent to it modified the tint of the skin to a greyish 
pink. The larger part of the ventral aspect had a similar colour, but the 
lower lips and the skin covering the mandible were greyish like the upper 
lips. The sides and ventral ridge of the compressed body in front of the 
tail were greyish and the cuticle was not pigmented. The ventral surface 
of the tail was greyish pink. 
The dorsum of the pectoral limb was grey interspersed with black 
streaks and spots. A greyish white band marked the anterior border and 
part of the dorsum, where it joined the side of the body. The ventral 
surface of the limb was grey. 
The characteristic furrows on the ventral surface, though shallow, 
proclaimed the foetus to be a Rorqual of the genus Balmnoptera. The 
form and relative size of the pectoral limb, the position of the dorsal fin 
vertically above the genital opening, the triangular beak with its straight 
lateral borders are characters present in Balcenoptera rostrata. The boss- 
like prominence on the summit of the head of the foetus, which Mr 
Coughtrey had also noticed in the parent animal, is a character which has 
been figured in the North Atlantic B. rostrata and strengthens the identi- 
fication of the species.* The tympanic bone from the adult was without 
question that of rostrata. The testimony of these specimens established, 
therefore, this species as frequenting the South Atlantic. 
The collection included several triangular plates of Whalebone, which 
varied in length from 11 to inches, and in greatest breadth from 5 to 
2 1 inches. The colour pattern was uniform : the outer half was black, 
inclining to dark grey near the middle of the plate ; the inner half was 
white with a slight yellow tint. The bristly hairs from the inner edge 
were white and delicate in texture. If this whalebone had belonged to 
the Minka Whale, it differed in colour from the baleen of the Northern 
B. rostrata, which is uniformly white or yellowish white. On the other 
hand, it approximated to the baleen of the Sye Whale, B. borealis, which is 
* In the presence of a low boss-like prominence on the top of the head, in the position of 
the dorsal fin, and in the form of the pectoral limb the foetus closely corresponds with the 
figure of a B. rostrata 15 ft. 4 in. long, in F. W. True’s great memoir on the Whalebone 
Whales of the North Atlantic, Smithsonian Contributions, Washington, 1904. 
VOL. XXXV. 
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