110—6 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
nearer to tlie superior surface of tlie ramus than in the existing sj)ecies. The mental 
foramen is j^laced nearer pm. 4, the dej^ression of the superior surface of the ramus 
in front of that tooth is less deep, and the ridge forming the anterior boundary 
of the masseteric fossa is more strongly developed. 
In its large size, as well as in the position of the mental foramen, and the 
strong development of the masseteric ridge, the fossil agrees with the Pikermi 
U. primigenia. In all other resj)ects that species appears to be very close to 
n. cristata, and differs, therefore, in the same characters from the Siwalik fossil. 
// (^?) lamandini is named upon the evidence of a fragment without the teeth, and in 
tlie absence of a figure cannot be compared with the present specimen. IT. refossa is 
apparently only known by a fragment of the mandilde containing one molar, and the 
alveolus of anotlier : it is said to be distinguished from IT. cristata by the more 
numerous enamel-islands on the worn crowns of the molars. It apparently agrees 
with the Siwalik form in having very distinct roots and short crowns to the molars ; 
but these teeth are of a more elongated form. IT. venusla is founded on a single 
molar, which is said to resemble the corresponding tooth of IT. cristata. It appears, 
however, to have had a short crown, with distinct fangs. It is impossible to say 
whether it is the same as the Siwalik fossil ; although this is improbable. There are 
no means of comparing the Siwalik specimen with the unnamed fossils from the 
Val d’Arno and Sicily. 
Young skull. — In the accompanying woodcut (fig. 5) there is represented the 
cranium of a young Siwalik porcupine in the British Museum whicli not improbably 
Fig. 5. Wystrix sp. Left lateral aspect of the cranium of a young individual from the Siwalik 
Hills, with the nasals restored. British Museum (No. 15,923). ) . 
belongs to the same species as the mandible. The specimen is believed to be one 
of those collected by Baker and Durand ; and has the mandible (in a crushed con- 
dition) attached, which has been omitted from the figure. The cranium has 
suffered considerably from crush, and has lost the nasals and a part of the maxilla. 
In the upper jaw there are only two teeth, and but three in the lower ; thus show- 
ing that the specimen is not adult. The first tooth in each jaw is the milk-molar, 
and the second the first true molar. On the left side of the mandible the whole 
length of the crown of mTl is exposed ; and it is thus seen that in its lower part the 
dimensions of this tooth are similar to those of the corresponding tooth of the 
