182 



UNGULATA 



ORDER VII 



Metriotherium Filhol {Deilotherium, Spaniotherium Filhol). Large forms. 

 Phosphorites of Quercy. 



Frotodichobune Stehlin. Lower Eocene of Epernay. 



Homacodon Marsh. First and second superior molars sextubercular, third 



Fig. 247. 

 Lower molars of A, Anoplotherium laiijies Gervais sp. ; B, 

 DijHobune modicum Filhol ; C, Diplohune minus Filhol ; and 

 D, Xiphodon sp. Phosphorites, Quercy. (After Steinmann 

 and Doederlein.) 



Fig. 248. 



Dicliohum leporinum Cuvier. Phosphorites, 

 Escamps, Quercy. A, Two upper molars. 

 B, Lower last milk-molar and two first 

 molars, l/l- 



molar quinquetubercular, inferior molars quadritubercular, similar to those 

 of Dichobune and Helohyus Marsh. Middle Eocene (Bridger beds) ; Wyoming. 



Sarcolemur Cope. Inferior molars with much-pointed cusps. Middle 

 Eocene (Bridger beds). 



Diacodexis (Trigonolestes) Cope. Superior molars tritubercular. Lower 

 Eocene (Wasatch beds) ; Wyoming. D. (Pantolestes) brachystonms Cope. 



Tribe 3. SELENODONTIA. 

 Family 7. Xiphodontidae Flower. 



Cheek teeth selenodont. Superior molars with five or four crescents, intermediate 



cone in anterior half. Inferior fourth premolar and superior fourth premolar often 



J very .complex, the other premolars 



ji^ ot' ^ elongated. Feet slender, long, with 



two digits; median metapodials and 

 tarsalia distinct ; lateral metapodials 

 reduced to very small vestiges. Up- 

 per Eocene ; Europe. 



Xiphodon qracile Cuvier. Upper Eocene, Debruge (Vau- 

 cluse). A, Upper cheek teeth. B, Lower cheek teeth, s/4, 



The Xiphodontidae are slender- 

 and long- footed Selenodonts. In 

 their entire habit they most re- 

 semble the ruminants, especially 

 the Tragulidae and deer. The 

 genus Dichodon has typically 

 ruminant cheek teeth, and is dis- 

 tinguished from all other Selenodonts by the similarity of the posterior pre- 

 molars to the true molars. 



Amphimeryx Pomel {Hyaegulus Pomel ; Xiphodontherium Filhol). Attains 

 the size of Tragulus. Xiphodon Cuvier (Figs. 247, D, 249). Of about the size 

 of a deer, have five crescents in the superior molars. 



Dichodon Owen. Superior molars are only quadricrescentic. Premolars 

 simple, the first caniniform, far from the second. Lower jaw low. Oligocene 



