55 



form and proportions with the same portion of the jaw in Palaosyops palu- 

 dosus, excepting that the masseteric fossa is much deeper. The -preser- 

 vation of the angle of the jaw, not retained in any of the previous specimens of 

 Palaeosyops, permits the determination of its character. It presents a nearly 

 semi-circular border projecting moderately below the base of the bone, and in 

 a less degree posteriorly. Toward the base it is somewhat bent inward. 



The last molar, in a restored condition, of the natural size, is represented 

 in Fig. 14, Plate XXIII, but, unfortunately, the artist has made its thickness 

 in front proportionately too great. 



The measurements of the specimen are as follows: 



Palseosyops Palaeosyops 

 major. j paliidosus. 



Distance from last- molar to back border of jaw 



Depth from condyle to bottom of angle 



Depth of jaw below fore part of last molar. . . . 

 Thickness of jaw below fore part of last molar . 



Breadth of last molar tooth 



Width at fore part of last molar tooth 



Width at middle part of last molar tooth... 



r Anea. 



lines. 



01 



4!) 



72 





35 



30 



10 



14 



22 



10 



13 



10J 



11^ 



n 



Fragments of another jaw similar to the above, and presenting the same 

 comparatively deep masseteric fossa, were found by Dr. Coi'son at Grizzly 

 Buttes. 



Fig. 2, Plate XXIV, represents a mutilated facial portion of a skull appar- 

 ently referable to Palceosyops major. The specimen was found on one of the 

 buttes of the Bridger formation by a- Shoshone Indian, and brought to Dr. 

 Carter, by whom it was presented to the writer. Though much distorted in 

 form, it gives us a fair idea of the shape and construction of a portion of the 

 skull of Palaeosyops that we had not previously had the opportunity of ex- 

 amining. It is crushed in such a manner that the upper part of the face is 

 pressed downward and toward the right side, and the orbit has its roof 

 brought near to the floor, so that it looks as if it were closed behind by the 

 presence of a postorbital bridge. 



The specimen shows that the form and construction of the face of Palaeo- 

 syops are very similar to what they are in Palaeotberium. The upper part of 

 t lie face appears to have been directed in a moderately sigmoid course, nearly 

 horizontally from the bottom of the convex forehead to the end of the muz- 



