SUBORDER D 



ARTIODACTYLA 



183 



(Headon beds), Hampshire. D. ruspidatus Owen. Eocene Bohnerz of 

 Switzerland. D. mulleri Riitimeyer. D. solodurensis Stehlin. 



Family 8. Caenotheriidae Cope. 



Superior and inferior molars selenodont, qninquehbhercular ; crescentic intermediate 



cusps in the posterior half in superior molars. Tympanic bullae inflated and filled 



^ with cancellated bony tissue. Feet 



short, tetradactyl ; lateral digits 



slender, considerably shorter than 



median ones, and not reaching the 



ground. Upper Eocene, Oligocene 



and Lower Miocene ; Europe. 



The two genera Caenotherium 

 Bravard (Microtherium Meyer) 

 (Fig. 250) and Plesiomeryx Filhol 

 (Fig. 251) are very closely related. 

 The species were only about 

 twenty centimetres high, and 

 evidently lived in large herds. 



Fig. 250. 

 Ccwnotherium elonyaUirn Filhol. 



Fig. 251. 

 Upper Eocene (Phos- Plesiomeryx cadurcensis Gervais. Upper 

 phodtesr Esc'ainps (Lot). ^, Skull and lower jaw, lateral Eocene (Phospliorite.s), Quercy. .4, Fore foot, 

 aspect P Skull, upper s.=!pect. 2/3. c, Upper cheek teeth. ^-^ Hmd loot. 4/g. (After Schlos.ser.) The 

 D Lower teeth 1/1. bones without shading are re.stored. 



Their remains are especially abundant in the Quercy Phosphorites, and in 

 the Lower Miocene of Auvergne and the Mayence Basin. Oxacron Filhol, 

 from the Phosphorites, has short robust extremities. 



Family 9. Agriochoeridae Leidy.^ 

 Dentition usually complete, in a continuous series or with diastema. Dental 



1 Leidy, J., Proc. Amer. Philos. Soc, Pliilad., 1848, p. 47 ; Ibid., 1850, p. 121 ; Ibid., 1851, 

 p. 239.— Jour. Acad. Nat. Sci., Philad., 1869, vol. vii., pp. 71, 12,1,— Cope, E. D., Proc Amer. 

 Philos. Soc, Philad., 1884, vol. xxi., pp. 503-512. • — Douglass, E., Merycochoeriis. Ann. Carnegie 

 Mus., vol. iv., 1907. — Matthew, W. I)., Memoirs Amer. Mus. Nat. Hist., New York, vol. i., part 

 vii., 1901, pp. 395, 420. — Scott, W. B., Beitriige zur Kenntnias der Oreodontidae. Morph. Jalirb. , 

 vol. xvi., 1890. — On the Osteology of Agriochoerus. Proc. Amer. Philos. Soc, Philad., 1894, p. 

 243. — Thorpe. M. R., John Day Promerycochoeri. Amer. Jour. Sci., ser. 5, vol. i., 1921. — Wort- 

 man, J. L., On the Osteology of Agriochoerus. Bull. Ajuer. Mus. Nat. Hist., New York, 1895, 

 pp. 145, 178. 



