222 ON THE EXTINCT MAMMALIA OF 



extend forward towards the upper lateral border of the snout. Between the supra- 

 orbital prominences the forehead is transversely concave, and is narrowed towards the 

 nasals. The back parts of the latter are broad and incline towards each other, but 

 laterally turn downward upon the side of the face. The fronto-nasal suture forms a 

 double crescent, with the contiguous horns directed into the internasal suture, which 

 remains open. 



The occipital region is much mutilated in all the skulls under examination. It 

 appears to have been proportionately more prominent over the position of the occipital 

 foramen than in the Indian Rhinoceros. 



The occipital foramen is rather ovoid or sub-pyriform, and is about sixteen lines in 

 diameter. The occipital condyles have their long diameter but little inclined from a 

 vertical line. 



The pararaastoid process is less well-developed than in the Indian Rhinoceros, 

 while the mastoid process is proportionately quite as large. The latter is directed 

 obliquely forward, and has its apex nearly reaching the middle of the post-glenoid 

 tubercle. 



The entrance to the auditory meatus is a high archway between the mastoid and 

 post-glenoid tubercles, narrowing below and expanding outwardly. 



Base of the skull. Plate XXII, figure 1. — The glenoid cavity is directed more out- 

 wardly than in the Indian Rhinoceros, and is of greater proportionate breadth fore 

 and aft. The post-glenoid tubercle is more compressed, and proportionately broader 

 and shorter. 



The inferior cranial axis is straighter than in the Indian Rhinoceros. 



The basi-occipital is deeply and sharply carinated in the median line. 



The condyloid foramen occupies a deep concavity midway between the occipital 

 foramen and the paramastoid process, and a little over an inch from that of the oppo- 

 site side. 



The foramen lacerum holds the same relative position as in the Indian Rhinoceros, 

 but is proportionately smaller. The foramen ovale is distinct from the former, and 

 about half an inch obliquely in advance of it. 



The remaining characteristic foramina of the sphenoid hold the same relative 

 position as in the Indian Rhinoceros. 



The palatine gutter has nearly the same proportions and form as in the latter, but 

 does not extend quite so far forward. 



The hard palate is remarkable for its deep, narrow- arched form. The molar series 

 on each side in nearly straight lines convei'ge anteriorly, so that the first pair of 

 teeth are within three-fourths of an inch of each other, while the last pair are nearly 

 two inches apart. 



