n. S. GEOLOGICAL SURVEY 



MONOGRAPH 55 PLATE XLVI 



MODELS OF HEADS OF EOCENE TITANOTHERES, SHOWING BRACHYCEPHALY, MESATICEPHALY, AND 



DOLICHOCEPHALY 



A, Palaeosyops leidyi, brachycephalic. B, Manteoceras manteoceras^ mesaticephalic. C, Telmatherium ultimum, mesatice- 

 phalic. D, Dolichorhinus hyognathus, dolichocephalic. H, Horn s-welling 



