CHAPTER VII 



LEONTINIDAE 



THIS family was established to include a group of large, 

 heavily built ungulates, not unlike rhinoceroses in form, 

 which have rooted teeth, the molars being similar to those 

 of Rhinchippidae, i. e., composed of a wall and an anterior 

 and posterior lobes, but with the cristae either lacking or 

 little developed ; and with the second upper, and the third 

 lower incisors developed into tush-like caniniform teeth. 

 Two genera are especially abundant, Leontinia of the Des- 

 eado beds, and Colpodon of the Colpodon beds, the former 

 with the formula 3^3, the latter with f^-j. In many 

 ways, the family suggests Nesodontidae, and undoubtedly 

 belongs to that series, if not directly ancestral. The lower 

 molars are distinctly of the same type as in all the other 

 toxodonts, but show a tendency to become hyposodont. 



The following genera have been assigned by Ameghino 

 to the family. Some of them are based on very scant mate- 

 rial and I have ventured to suggest in each case what dis- 

 position I have felt to be the proper one. 



Leontinia, the type genus, is described in detail on pages 

 109-115. 



Scaphops is based on a mandibular symphysis, which is 

 wider than usual for Leontinia, and on a second upper 

 incisor which is compressed. The species in the genus 

 Leontinia show a marked degree of variability, and I can 

 see in this only individual variability, so that I place Scap- 

 hops under Leontinia and S. grypus, as a synonym of L. 

 gaudryi. 



Steniogenium is based on a mandibular symphysis with 

 roots only of the teeth. The incisors are proclivous and 

 inc. 3 small. I consider this also as Leontinia, and the 

 species S. sclerops as a synonym of L. oxyrhynca, which I 

 think is the female of L. gaudryi. 



