On Tiro Neir Species of Dicynodonts. 455 



is gone. Its transverse width is 34 mrn. and its antero-posterior 

 measurement about 20 mm. 



The occiput presents no unusual features. The condyle is rather 

 large, and the basi-occipital portion is demarcated from the 

 ex-occipital portions by distinct shallow depressions or grooves. If 

 these grooves indicate the original lines of suture, the basi-occipital 

 portion is about twice as large as either of the others. The trans- 

 verse width of the condyle is 44 mm., and the depth in the median 

 line 33 mm. Above the condyle on either side of the foramen 

 magnum is a very distinct and well-developed tubercle with a small 

 ridge running downwards and outwards from it. From near the 

 same region a feeble ridge runs upwards and outwards on the 

 moderately fiat supra - occipital. The ex-occipital is somewhat 

 massive, and its lateral portion stands out from the descending 

 part of the squamosal, which it supports. The par-occipital pro- 

 cesses though both broken off at the bases have evidently been 

 unusually well developed. 



On the inner side of the quadrate and practically on the suture 

 between it and the ex-occipital is to be seen the columdla anris. The 

 outer part is a cylindrical rod of about 2 mm. in diameter, but on 

 passing inwards, forwards, and upwards it becomes somewhat 

 flattened and very much thicker. Its total length has probably been 

 about 40 mm. A little farther out than the broken outer end of the 

 columella auris , and resting on the posterior side of the quadrate, are 

 indications of an additional bony element, but the fragment which is 

 left is too small and imperfect to give any certain indications as to 

 the nature of the structure. It may be the fragment of a malleus, 

 or it may be, as seems to me the more probable, the remains of an 

 ossified tympanic ring. 



OUDENODON TRUNCATUS, n. sp. (Plate X., fig. 4.) 



This species is founded on the anterior portion of a skull belonging 

 to the Port Elizabeth Museum. There is no history attached to the 

 fossil, but there is some reason to believe that it came from Hanover. 

 The fossil represents the almost perfect palate of a moderate-sized 

 species of Oudenodon. The palate is so beautifully weathered that 

 the sutures are quite distinctly shown. The premaxillary forms 

 practically the whole of the bony roof of the mouth, almost com- 

 pletely covering the under surface of the maxillaries. The specimen 

 further proves conclusively that the median ridge which has 



