394 PROF. FLOWER ON A NEW [May 2, 
the nares is thrown exceedingly to the left side. So far, however, 
there is nothing essentially different from Hyperoodon rostratus. It 
is in the region immediately in front and to the side of the blow- 
holes that the great difference is seen. his part in H. rostratus 
is characterized by the very prominent maxillary crests, the inner 
surfaces of which rise vertically from the outer border of the great 
‘infraorbital’’?! foramen, the two opposed surfaces being nearly 
parallel with one another, or even slightly hollowed, so that their 
summits have a tendency to inversion. Although the amount of 
elevation to which the corresponding crests might have attained in 
the new specimen cannot be satisfactorily ascertained, as their surfaces 
have evidently been subjected to the attrition previously alluded to, 
it is perfectly evident that they differed greatly in form from those 
Fig. 2. 
Side view of cranium of Hyperoodon planifrons. 
of H. rostratus, as the still unworn (because protected) inner surfaces 
slope gently outwards and upwards from the edge of the foramen, 
and the crests therefore, though with a base even broader from side 
to side than in H. rostratus, must have been low and rounded and 
quite devoid of any tendency to inversion. Another great difference 
(better seen in the side view, fig. 2) is that the crests do not sink 
abruptly at their hinder end, leaving a deeply depressed surface of the 
maxillary bone intervening between them and the occipital elevation, 
but they are continued backwards, above the temporal fossa, and so 
pass gradually into the occipital crests, forming a continuous outer 
wall to the great basin in which the blowholes are placed, which is 
completely interrupted in H. rostratus. Among minor differences, 
* Or the foramen corresponding to the infraorbital in man, in transmitting 
the branch of the fifth pair of nerves that supplies the cheek and upper lip, but 
not infraorbital in position in the Cetaceans, 
