48 



referred to Palaosyops major, and the jaw-specimen, with teeth, of P. palu- 

 dosus, are as follows : 



Palmosyops 



major. 



Palaeosyops 

 paludostiB. 



Depth of jaw at middle of last molar 



Depth of jaw at middle of last premolar 



Thickness of jaw below interval of last two molars 



Thickness of jaw below third premolar 



Distance from canine alveolus to back of last molar 



Length of the complete molar series 



Length of the molar series, excluding the first premolar 



Length of the molar series, excluding the first two premolars. 



Length of the premolar series 



Length of the true molar series 



Breadth of second premolar ' 



Thickness of second premolar 



Breadth of third premolar 



Thickness of third premolar 



Breadth of fourth premolar 



Thickness of fourth premolar 



Breadth of first molar 



Thickness of first molar 



Breadth of second molar 



Thickness of second molar 



Breadth of third molar . - 



Thickness of third molar , 



Lines. 

 37 

 20 

 10 

 14 

 92 

 90 

 82 

 72 

 38 

 53 



9 



5 



8| 



5% 



n 



7 

 9 



m 



10f 



24 



13J 



Lines. 



Lines. 

 32 

 23 

 13 



m 



177 







08 



04 



51 



40J 







8 

 

 8| 



13J 



H 



10£ 



22 

 12 



8* 



9 



8 

 15 



19 

 10 



Some additional specimens, found by Dr. Corson in the buttes of Dry 

 Creek Cation, appear to belong to the larger Palseosyops. These consist of 

 some upper teeth, comprising a canine, a second and last premolar, and the 

 second and third molars. 



The latter are represented in Figs 10, 11, Plate XXIII, and they agree 

 in character with the corresponding smaller teeth described under the head 

 of Palceosyops paludosus. They are but slightly worn at the summits of the 

 lobes of the crown, and the enamel is conspicuously wrinkled. 



The last premolar, represented in Fig. 9, of the same plate, likewise agrees 

 with the corresponding tooth described under the head of Palceosyops palu- 

 dosus, except that it is of larger size. The tooth is but slightly worn, and 

 exhibits a much less wrinkled condition of the enamel than the true molars. 



The second premolar, represented in Fig. 8, resembles in form that of the 

 second series of specimens of upper molar teeth, described under the head of 



