28 Guide to Whales, Porporses, and Dolphins. 
case is exhibited a skull from South Africa of Layard’s Beaked 
Whale (I. layardt), the species referred to above as remarkable 
for the extraordinary development of the single pair of lower 
teeth. A skull of the New Zealand Beaked Whale known as 
M. hectori is likewise placed in this case. 
Near by is shown a skeleton of the Chatham Island Beaked 
Whale (Ziphius chathamensis), from New Zealand, collected 
by Sir Julius von Haast. The specific distinction between this 
Beaked Whale and the typical 7. cavirostris is not well established. 
Of the latter, two skulls are shown in the table-case, both from 
South Africa; one of these, like the skull of Layard’s Beaked 
Whale (fig. 12), was presented by the Trustees of the South 
African Museum ; the other was acquired by purchase. 
Berardius arnuxi is represented only by a single tooth, from 
New Zealand; it is of the large size distinctive of the genus. 
In a table-case at the south end of the gallery, next the one 
with the recent skulls of the same group, are displayed a number 
of remains of extinct Beaked Whales. These most commonly 
take the form of the solid beaks, or rostra, of the skull, which are 
preserved in the “Crag” of East Anglia, as well as in other late 
Tertiary Deposits. Some of these beaks are referred to the exist- 
ing genus Mesoplodon, but others indicate distinct generic types. 
Among the latter, Choneziphius differs from Mesoplodon in the 
relations of the premaxille to the vomer, in the small portion of 
the latter exposed on the under surface of the beak, and also in 
the presence of a hollow tube in the latter, due to the non- 
ossification of the mesethmoid cartilage. 
Battiecnased The Bottle-nosed Whale ({yperoddon rostratus) 
Whale: also belongs to the family Ziphude, of which the 
characteristics are given in the paragraph devoted 
to the Beaked Whales. The muzzle is elongated into a beak, 
from above which rises somewhat abruptly an eminence formed by 
a cushion of fat resting on the skull in front of the single 
crescentic blow-hole. From its allies the Bottle-nose is distin- 
guished by having a single pair of teeth, concealed during life in 
the gui, at the extremity of the lower jaw, and also by the great 
development—especially in the adult—of the pre-maxillary crests 
of the skull. This species is one of the commonest of British 
Cetaceans, and feeds chiefly upon cuttle-fishes and squids. Males 
grow to 30, and females to 24 feet. It yields a kind of spermaceti 
