96 “TERRA NOVA” EXPEDITION. 
the beak, arranged approximately in two alternate series of four: an outer row on the 
extreme edge of the beak, and an inner row situated a short distance away from the 
edge; making in all about twenty-seven tubercles on the upper jaw. On either side 
of the lower jaw there were about eight hair-tubercles, also arranged in two more or 
less alternating rows of four. On each side of the blunt extremity of the mandible, 
pointing directly forwards, there was a cluster of two or three larger tubercles and a 
few smaller ones. These clusters contained the largest of all the hair-tubercles, and 
constituted the foremost part of the animal. 
A— Anterior view of the mouth of a Humpback, to show the movement of the rami of 
the lower jaw (semi-diagrammatic) : a, free ends of the baleen-plates ; b, tongue 
seen through the space between the lips; c, rami of mandible in the position 
which they occupy when the mouth is open ; d, upper jaw ; e, hair-tubercle. 
B—Transverse section of the symphysis between the rami of the lower jaw: a, white 
fibrous tissue ; b, central pulpy substance. 
There were, altogether, about twenty-eight tubercles on the lower jaw. The 
number and character of the tubercles corresponded very closely with those described 
as occurring on the Northern MJegaptera.* 
The lengths of the hairs when withdrawn from their follicles were, on an 
average, about 32 mm. The longest observed was 45 mm. The free portion of 
True, F. W., “ Whalebone Whales of the Western North Atlantic,” Smithsonian Contributions 
to Knowledge, 1904, Vol. XX XIII, p. 225, 
