96 ON THE EXTINCT MAMMALIA OF 



8. The mutilated facial portion of a skull of somewhat peculiar appearance. The 

 specimen is more robust than the corresponding portion of the others usually are, and 

 is about the size of that of No. 5. The teeth are of intermediate size. The orbits 

 appear to have exhibited the usual form. The lachrymal fossse are more than usually 

 shallow. The forehead and contiguous portion of the face exhibit a more uniform and 

 rather greater convexity than usual. The posterior ends of the nasal bones, between 

 the frontals, are sigmoid at the sides, and comparatively deeply and widely notched at 

 the summit. In this specimen the back part of the frontals are co-ossified. The tem- 

 poral ridges, as in the preceding specimen, commence with the summit of the frontals. 

 The grooves from the supra-orbital foramina diverge more than usual and descend 

 upon the frontal angular processes some distance from the nasal bones. 



9. The greater part of the fiicial portion of a skull, somewhat resembling the last 

 specimen, but of smaller proportions. Though not from an aged animal, as indicated 

 by the condition of the teeth, yet most of the sutural connections of the bones pre- 

 served in the specimen are completely obliterated, including the frontal, the fronto- 

 nasal, the fronto-lachrymal of one side, the frouto-maxillary of the same side, both 

 lachrjono-maxillaries, and the inter-nasal partially. 



10. The facial portion of a skull, without the lower jaw, represented in figure 3, 

 plate IX. It is remarkable for its size, as the specimen is not only much larger than 

 the corresponding portion of an}' of the preceding specimens, but approximates in size 

 that of some of the smaller skulls of Oreodon Culbertsoni. It has, however, small 

 orbits, comparatively shallow lachrymal fossae, and the posterior ends of the nasal 

 bones together form a half-ellipse, nine lines long and ten lines wide, between the ends 

 of the frontal angular processes. The teeth, though larger than usual, are not . quite 

 so large as in specimens No. 5 and 6. The specimen is again referred to as represent- 

 ing a doubtful species under the name of 0. affinis. 



11. The greater part of a lower jaw, with all the teeth except the incisors and one 

 canine. 



12. The greater part of a skull, including the lower jaw, obtained by Dr. Hayden, 

 in his expedition to the Mauvaises Terres, in the summer of 1866. The collection 

 made in the expedition just mentioned contained another skull of 0. gracilis, besides 

 fragments of half a dozen others. 



The comparative measurements of these specimens are given in the following table, 

 the number of the specimens corresponding with the numbers at the head of the 

 latter : 



