210 EVOLUTION AND DISEASE. 
fessor Sir W. Turner. The illustration (fig. 112), which 
was prepared from a model of this specimen, represents — 
the anterior part of the rostrum and lower jaw with two 
teeth of MWesoplodon layardi. ‘This whale has only one 
tooth in each mandible (at least, as far as we know). In 
the present case the fangs of these teeth had become 
ereatly elongated, and after emerging from the gum had 
curved backwards, upwards, and inwards, so as to cross 
each other on the dorsal surface of the whale’s beak. 
The anterior border and inner surface of each tooth was 
Fic. 112.—The rostrum of Mesoflodon layardi, showing the curved 
and elongated mandibular teeth. 
smooth where they rubbed together during the move-— 
ments of the mouth. The size of these teeth is as 
follows :— The extracted tooth measures 35 centimetres, 
16 of which were embedded in the alveolus, or surrounded 
by the gum. The breadth of the tooth where it emerged 
from the alveolus was 9 centimetres. At the time this 
specimen was submitted to Turner, he was fortunate 
enough to receive a young specimen of Mesoplodon 
which enabled him to determine the nature of the 
various parts of this abnormal tooth, and he came to_ 
