PLATE LII. 



Figures all oue-half natural size, ext;e[)t Fig. 6. 



Fig. 1. — Mandible jjf Palaeosijops major. Page 701, superior view. 



Fig. "2. — Superior view of Fig. 1. 



Fig. 'A. — Mantlible of Palaeosyops valUdens, figured in Plate LIII, page 699, superior view. 



Fig. 4. — Superior molar tooth of jEf2/racfii/M« ^jrijicfps. From South Bitter Creek, Wyoming. Page 661 



