PLATE X 



PAGE. 

 Fig. 1-4. Chomatodus Varsouviexsis, St. J. and "W 363 



1 a. View from above; 1 b, convex face; 1 c, profile section. "Warsaw beds; above 



Alton, Ulinois. 



2 a, b, c. Similar views of a larger, worn specimen. Same horizon and locality. 



3 a, b, c. Similar views of large tooth, showing extravagantly developed convex crown face 



Same horizon ; Barrett's. Missouri - 



4 a. Fragment of oblique tooth, seen from above; 4 b, profile section. Same horizon, 



above Alton, Illinois. 



Fig. 5-14. Chomatodus tncoxstaxs, St. J. and TT 360 



5 a. Concave face of tooth of ordinary appearance ; 5 b, opposite face, base restored in 



outline ; 5 c, profile section, showing uearly vertical root. St. Louis limestone ; 

 Pella, Iowa. 

 6« A long, slender tooth seen from above; 6 b, convex aspect ; 6 c, profile section. 



Same horizon and locality. 



7 a. Concave face of small tooth, irregularly serrated along crest; 7 6, convex face ; 7 c, 



profile section. Same horizon and locality. 



8 a f b, c. Similar views of small tooth with oblique root. Same horizon and locality. 



9 a, b, c. Similar views of tooth with extremely oblique root. Same horizon and locality. 



10 a, b, c. The same views of a more regular tooth, with oblique base. Same horizon and 



locality. 



11 a, b, c. Similar views of a more eccentric tooth. Same horizon and locality. 



12 a, b, c. Similar views showing both faces of base and the beveled inferior surface. Same 



horizon and locality. 



13 a. View from above of large tooth, with nearly median crest ; 13 b, convex face, show- 



ing relatively shallow root ; 13 c, profile section. Same horizon and locaUty. 



14 a. Profile section of large specimen with vertical root, both faces of crown vertically 



concave. Same horizon and locality. 



Fig. 15-17. Chomatodus Chesteuexsis, St. J. and "W* 363 



15 a. Medium-sized tooth, seen from above; 15 b, convex face, showing deep base; 15 c, 



profile section. Chester limestone ; Chester, Illinois. 



15 a. Concave face of fragment of small tooth, with oblique base; 16 b, convex face; 



16 c, profile section. Same horizon and locality . 



17 a, o, c. Similar views of large, nearly perfect tooth ; 17 d, view of crown from above, show- 

 ing nearly median crest- Same horizon and locality. 



Chomatodus ixcuassatus. St. J. and "W 359 



View of concave face of medium-sized tooth, enlarged two diameters ; 13 6, convex 

 face and base ; 18 c, profile section. St. Louis limestone ; Alton, Illinois. 

 Chomatodus comptus, St. J. and W 356 



Concave aspect of large, symmetrical tooth, showing base and beveled inferior sur- 

 face ; 19 b t view of convex face ; 19 c, outline of crown from above ; 19 d, e, 

 profile sections. Upper Burlington ; Louisa county, Iowa. 



Similar views of short, robust tooth. Same horizon and locality. 



Same views of a similar shaped, smaller tooth. Same horizon and locality. 



Similar views of small tooth. Same horizon and locatity. 



Chomatodus aecuatus, St. J 000 



View of concave crown-face, showing part of base ; 23 b, convex crown-face, base 

 partially restored ; 23 c, view of crown from above ; 23 d, profile section. Upper 

 Coal Measures, Adams county. Iowa. 



Fig. 



18 









18 



a. 





Fig. 



19 



.22. 







19 



a. 







■20 



a,b, 



c. 





21 



a. b. 



c. 





22 



a, &, 



c. 



Fig. 



23. 









S3 



a. 





