108 “TERRA NOVA” EXPEDITION. 
correspond in function to the ossified tympanic membrane and the extra-columella 
expansion in Plioplatecarpus. The bony septum formed by the vomer, together with 
the pterygoid and periotic bones, the bulla and ossicles, would perform the function of 
the columella in the whale-like reptile. 
If neither one nor the other of the above modes of sound-conduction be correct, it 
is difficult to understand how these whales hear. Yet it is firmly believed by whalers 
that they are sensible of the report of a gun and similar sounds. 
SCAPULA AND VERTEBRAE. 
The shape of the scapula was identical with that of the Northern JJegaptera.* 
There was no sign of an acromion process on the blade-bone of any of the adults, or on 
that of the 134 ft. foetus. (Text-fig. 12.) This point was carefully examined, as the 
occurrence of an acromion process on the scapula was said to be one of the specific 
Fig. 12.—Megaptera nodosa, Bonn. Scapula of 134 feet foetus. Fic. 13.—Left scapula of New Zealand 
Bay of Islands, N.Z. Humpback whale (adult): C.P., 
coracoid process. 
characters of JZ. lalandi Fischer.t There was a slight trace of the coracoid process. 
(See text-fig. 13.) In other osteological characters the New Zealand Humpback 
was in agreement with Northern types. The vertebral formula was ascertained in one 
case and found to be C. 7, D. 14, L. 10, C. about 20. The cervical vertebrae were 
not united in the young specimen. It is extremely probable that the anterior cervicals 
in this species become fused in old age. 
* Cabrera, A., ‘ Fauna Ibérica. Mamiferos,” Madrid, 1914, Cetacea, p. 398. 
{+ Van Beneden et Gervais, “ Ostéographie des Cétacés,’ p. 133. Turner, W., ‘“ Challenger” 
Reports, Vol. I., p. 30. 
