NO. 6 PALEOCENE FAUNAS OF BISON BASIN — GAZIN 55 



Plate 4 



plesiadapis from the bison basin paleocene 



Figs. 1-3. Plesiadapis jepseni, new species: I, Left ramus of mandible 

 (U.S.N. M. No. 20586), lateral and occlusal views ; 2, left maxilla (U.S.N.M. 

 No. 20781), occlusal view; 3, left ramus of mandible (U.S.N.M. No. 20760), 

 type specimen, lateral and occlusal views. Three times natural size. 



Plate 5 

 tricentes and chriacus from the bison basin paleocene 



Figs. I, 2. Chriacus, near C. pehndcns (Cope) : i, Right ramus of mandible 



(U.S.N.M. No. 20983), lateral and occlusal views; 2, left M**? (U.S.N.M. 



No. 21003), occlusal view. Two and one-half times natural size. 

 Fig. 3. Chriaciis, sp: Left M^? (U.S.N.M. No. 21019), occlusal view. Two and 



one-half times natural size. 

 Fig. 4. Tricentes jremontensis, new species: Left ramus of mandible (U.S.N.M. 



No. 20582), type specimen, lateral and occlusal views. Two and one-half 



times natural size. 



Plate 6 



tiiryptacodon from the bison basin paleocene 



Fig. I. Thryptacodon belli, new species: Right ramus of mandible (U. of Wyo. 



No. 1045), type specimen, lateral and occlusal views. Twice natural size. 

 Fig. 2. Thryptacodon, cf. dcmari, new species: Left maxilla (U.S.N.M. 



No. 20984), occlusal view. Twice natural size. 

 Fig. 3. Thryptacodon demari, new species : Right ramus of mandible (U.S.N.M. 



No. 20985), type specimen, lateral and occlusal views. Twice natural size. 

 Fig. 4. Thryptacodon, cf. belli, new species : Left maxilla (U.S.N.M. No. 20986), 



occlusal view. Twice natural size. 

 Fig. 5. Thryptacodon, cf. australis Simpson: Left ramus of mandible (U. of 



Wyo. No. 1076), occlusal and lateral views. Twice natural size, 



Plate 7 

 claenodon from the bison basin paleocene 



Figs. I, 6. Claenodon acrogenius, new species: i. Left ramus of mandible 

 (U.S.N.M. No. 20575), occlusal view, natural size; 6, right ramus of man- 

 dible (U.S.N.M. No. 20634), type specimen, lateral view, one-half natural 

 size. 



Figs. 2, 3. Claenodon, cf. ferox (Cope) : 2, Left ramus of mandible (U.S.N.^L 

 No. 20633), occlusal view; 3, right maxilla (U.S.N.M. No. 20797), occlusal 

 view. Natural size. 



Fig. 4. Claenodon, cf. montanensis (Gidley) : Left ramus of mandible (U.S.N.M. 

 No. 20574), occlusal view. Natural size. 



Fig. 5. Claenodon, cf. procyonoides (Matthew): Right ramus of mandible 

 (U.S.N.M. No. 20630), lateral and occlusal views. Twice natural size. 



