
PLATE CXa. 
~SkuLus or Jonn Day DicoTyLip2 
Nomenclature 
Cope 1880-3 Revised, 1913 
Paleochcerus subequans Perchcerus subsequans 
Paleochcerus trichzenus Perchcerus trichzenus 
Cheenohyus decedens Chenohyus decedens 
Fic. 1. Perchwrus subaquans (Cope) 1879. Skull and lower jaw. Type specimen, Condon 
Coll., University of Oregon. Three-fourths natural size. 
Fic. 2. Percherus trichenus (Cope) 1879. Upper jaw of type specimen, Amer. Mus. No. 7390, 
Cope Coll., John Day formation, Oregon. Three-fourths natural size. 
Vic. 3. Chanohyus decedens Cope 1879. Upper jaw of type specimen, Condon Coll., University 
of Oregon. Natural size. 

