351—174 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
ADDENDUM. 
Mandible of Lutra sivalensis. — Since the description of Lutra sivalensis was 
printed a fragmentary specimen of the mandible of that species, represented in plate 
XLV., figs. 3, 3a, has come under the writer’s notice. This specimen is in the 
Ipswich Museum, to which it was presented, with some other Siwalik fossils, by Miss 
Cautley ; haying doubtless been obtained by Sir P. T. Cautley. It comprizes the 
hinder portion of the right ramus, and shows the root of m. 2, and the carnassial 
(m. l), of which the anterior half is broken: the condyle, angle, and the summit of 
the coronoid process are likewise wanting. The shape of m. 1, the mode of 
implantation of m. 2 (which is set close into the anterior border of the ascending 
ramus, and very obliquely to the alveolar line of the other cheek-teeth), and the 
form of the masseteric fossa (characterized by its great depth and the regular 
curve of its anterior border) show that the specimen belongs to an otter ; while the 
large size of the specimen indicates that it should be referred to Lutra sivalensis. 
The last true molar (m. 2) is implanted by a single fang, as in all living otters. The 
carnassial has been partially worn : its talon has precisely the same structure as in 
other otters, but its central depression is slightly less deep : the bases of the hinder 
cusps of the blade which still remain, show that these also occupied the same relative 
position. The depth of the jaw, as in Lutra lathy gnatlius , exceeds the length of the 
carnassial, indicating, in conjunction with the great depth of the masseteric fossa, 
the enormous biting power of the animal. In all other respects the specimen agrees 
with the jaws of living species of otter. The length of the carnassial is 084, and 
the depth of the jaw below this tooth P25 inches. 
This unique specimen confirms the conclusions previously arrived at as to the 
generic identity of the gigantic Siwalik otter with Lutra ; and also as to the specific 
distinctness of L. lathygnathus. 
