36 



and I he specimens of leetli from Henry's Fork, just described, are as 

 follows : 



Space occupied by the entire molar series 

 Space occupied by the true molar series 

 Space occupied by the premolar series . . 



Lines. 



G9 

 41 



28 



Lines. 



71 

 41 

 32 



Diameter 

 Diameter 

 Diameter 

 Diameter 



Diameter 

 Diameter 

 Diameter 



of first premolar . . 

 of second premolar 

 of third premolar . 

 of fourth premolar 



of first molar 



of second molar . . . 

 of last molar 



Antero- 

 posterior. 



Lines. 



5 



G 



7 

 10 

 12 

 10 

 17 



Transverse. 



Lines. 



3 



7 



8 

 10£ 

 13 

 17 



Antero- 

 posterior. 



Lines. 



7 



8 



8 



8 

 12 

 15 

 17 



Transverse. 



Lines. 



4 



7 



9 

 10 

 12A 

 16 

 16J 



Lines. 



Lines. 



Length of fang of upper canines 



Autero-posterior diameter of canines. 

 Transverse diameter of canines 



28 

 10£ 



18 



H 



7 



The question arises whether the differences which have been indicated in 

 the premolars and canines of the two different series of teeth above described 

 indicate more than one species. The differences are clearly in degree of 

 development and size, and these may probably be of a sexual character. The 

 individual with the more powerful canines I suppose to have been a male, in 

 which, with a greater proportionate degree of development of these organs 

 than in the female, there appears to have been a reduction in the degree of 

 development of the anterior premolars. 



Another specimen submitted to my examination by Dr. Carter, and repre- 

 sented in Figs. 6, 7, Plate XXIV, belonged to an older animal than the 

 former, as indicated by the more worn condition of the teeth. The latter 

 consist of the anterior three premolars and a portion of the fang of the canine, 

 and they have the same form and proportions as the corresponding teeth 

 above described. The first premolar is close to the others, or is not sepa- 



