196—20 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
and also, of about half the natural size, in plate XXVII. of the first volume of the 
“ Palaeontological Memoirs.” In addition to these specimens there is a specimen of 
the facial portion of the skull in the Museum, of the Royal College of Surgeons, obtained 
from the Siwaliks, and presented by the late Rev. R. Everest. This specimen (by 
the permission of the Curator of the Museum) has been (for the first time) figured 
from the palatal aspect in figure 5 of plate XXVII. of the present memoir ; and 
since its cheek-teeth are in better preservation than those of any of the other 
specimens, it is mainly these teeth that are compared with those of other species of 
otters. 
It may be observed in the first place that all the four skulls exhibit essentially 
lutrine characters ; — more particularly the shortness of the facial portion of the skull, 
the post-orbital contraction of the frontals, the sudden lateral expansion of the brain- 
case, and the enormous relative size and extreme shortness of the infra-orbital 
foramen for the passage of the fifth nerve (“ Pal. Mem.,” jdI. XXVII., fig. 1). The 
skulls show a considerable amount of variation in the relative degree of development 
of the sagittal crest, probably indicating differences of sex and age in the different 
specimens. In the specimen figured in the present memoir this crest is very 
prominently developed ; whence it may probably be inferred that the skull belonged 
to a fully adult male. The same may also be affirmed of the skull represented 
in figure 5 of the above-mentioned plate of the “ Palaeontological Memoirs ”; 
whereas the other two skulls in the same plate probably belonged to female 
individuals. The skull represented from the palatal aspect in figure 4 of the same 
plate, which is the only one with the brain-case, shows that the auditory bulla was 
triangular and depressed, as in the living otters. 
The state of preservation of the crania is not sufficiently perfect to admit of 
any closer comparisons ; but there are no indications of any characters generically 
different from those of the living otters. 
Upper dentition . — In the specimen represented in figure 5 of plate XXVII. there 
are shown the complete true molars and carnassials of each side : there are also 
shown the bases of pm. 3 , but no traces of pm. 2 . The alveoli of the canines, and of 
the three incisors are also shown : the latter somewhat indistinctly. In the specimen 
represented in figure 2 of the above-mentioned plate of the u Palaeontological 
Memoirs ” the alveoli of pm. 2 are distinctly shown. 
The complete dentition is, therefore, numerically the same as that of the otter 
represented in the woodcut (fig. 2) on page 187. Commencing with m. 1 , it will be 
found that this tooth has precisely the same form as the corresponding tooth of the 
otter represented in figure 1 of the same plate, which has been shown to be related 
to the long-clawed otters. The cusps on this tooth correspond precisely to the cusps 
of the tooth of the otter figured on page 187. In the carnassial ( pm. 4 ), however } 
there are very considerable differences from the corresponding tooth of all living 
otters. To illustrate more fully these differences, the left upper carnassial, partly 
