l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 28 



faunal exchange initiating Oliogocene time, with the appearance on 

 this side of anthracotheres, choeropotamids, and probably other forms. 



CLASSIFICATION 



The following is the revised classification of the upper Eocene 

 artiodactyls as adopted in this study : 



DICHOBUNIDAE Gill, 1872 

 HoMACODONTiNAE, Petersoii, 1919 

 Bunomeryx Wortman, 1898 

 Bunomcryx elegans Wortman, 1898 

 Bunomeryx montanus Wortman, 1898 

 Hylomeryx Peterson, 1919 



Synonym: Sphenomeryx Peterson, 1919 

 Hylomeryx annectcns Peterson, 1919 

 Hylomeryx quadricuspis (Peterson), 1919 

 Mesomeryx Peterson, 1919 



Mesomeryx grangeri Peterson, 191 9 

 Pentacemylus Peterson, 1931 

 Pentacemylus progressus Peterson, 1931 

 Pentacemylus leotensis, new species 

 Mytonotneryx, new genus 

 Mytonomeryx scotti, new species 

 Helohyinae (Marsh, 1877, as Helohyidae) 

 Achaenodon Cope, 1873 



Synonym : Protcolothcrium Osborn, 1895 

 Achaenodon insolens Cope, 1873 

 Achaenodon robtistus Osborn, 1883 

 Achaenodon tiintcnsis Osborn, 1895 

 Parahyus Marsh, 1876 



Parahyus vagtis Marsh, 1876 

 HYPERTRAGULIDAE Cope, 1879 

 Hypertragulinae Matthew, 1908 

 Simimeryx Stock, 1934 



Siniimeryx hudsoni Stock, 1934 

 Simimeryx miniitus (Peterson), 1934 

 AGRIOCHOERIDAE Leidy, 1869 



Protoreodon Scott and Osborn, 1887 

 Synonyms : Eomeryx Marsh, 1894 

 Hyomeryx Marsh, 1894 



Agriotheriiim Scott, 1898 (not Wagner, 1837) 

 Chorotheriiim Berg, 1899 

 Protagriochoerus Scott, 1899 

 Mesagriochoerus Peterson, 1934 

 Protoreodon pumilns (Marsh), 1875 



Synonyms : Protagriochoerus annectcns Scott, 1899 

 Protoreodon mediiis Peterson, 1919 

 fProtoreodon tardus Scott, 1945 

 Protoreodon parvus Scott and Osborn, 1887 

 Synonym : Hyomeryx breviccps Marsh, 1894 



