PLATE I 



PAGE. 



Fig. 1-6. Cladodus exilis, St. J. and TV 258 



1 a. Outline of minute tooth. ; 1 b, view of outer face, enlarged, showing two lateral denti- 



cles on one extremity and three in the opposite ; 1 c, base from below ; 1 d, profile 

 section. Lower fish-bed, Kinderhook. 



2 a. Outline of slightly larger tooth, with three lateral denticles on either side; 2 b, 



outer surface, enlarged ; 2 c, base from below ; 2 d, profile section. Same horizon. 



3 a. Outline of medium-sized, robust tooth; 3 6. view of outer face, enlarged; 3 c, post- 



erior face; 3 d, inferior basal surface; 3 e, profile section. Upper fish-bed, 

 Kinderhook. 



4 a. Outline of small worn tooth, with two lateral cones on either side; A b, outer face, 



enlarged; Ac. posterior face; Ad, e, base from below, and profile section and 

 transverse section of medium cusp. Same horizon. 



5 a. Front view of small, perfect tooth, enlarged ; 5 b, c, inferior basal surface aDd profile 



section. Same horizon. 



6 n. Outline of imperfect tooth of large size; f>b,c, outer and posterior faces, enlarged; 



6 d, e, base from below and profile section. Same horizon. 



Fig. 7. PfllSTICLAUODUS Sthixgbht, St. J. and W 255 



7 a. Outline, nat. size ; 7 b, view of outer face, enlarged ; 7 c, inferior basal surface ; 7 d, 



profile section and transverse section of median cone. Lower fish-bed, Kinderhook. 



Fig. 8-11. Pkistici-adodus SrnixGEm, var. armatus, St. J. and TV 256 



8 a. Outer face of large tooth, enlarged three diameters; 8 b, inferior basal surface, show- 



ins: worn protuberances in front, and median foramen in posterior margin. 

 Upper fish-bed, Kinderhook, 



9 a. Front view of similar specimen, enlarged two diameters ; 9 &, posterior face, showing 



broad convexity of upper basal surface; 9 c, inferior basal surface, showing pad- 

 like prominences in front less worn than in the preceding example ; 9 d, profile 

 section. Lower fish-bed, Kinderhook. 



10 a. Outline of small tooth, showing anteroinferior basal promineuces; 10 b, front view, 



enlarged. Same horizon. 



11 a. Anteiior view of minute tooth, enlarged ; 11 &, posterior face ; 11 c, base from below, 



showing widely spaced protuberances. Same horizon. 

 Fig. lrf, 13. Batiitcheilodus McIsaacsii, St. J. and TV 252 



12 a. View of outer face of large tooth, enlarged; 12 b, posterior aspect; 12 c, profile and 



transverse sections of median cusp, iliddle Devonian, "Waterloo, Iowa. 



13 a. Front view of small, nearly perfect tooth, enlarged ; 13 6, posterior face ; 13 c, inferior 



basal surface ; 13 rf, profile section. Same horizon and locality. 



Fig. 14, PnoEiiouus Sophias, St, J. and TV 251 



14 a. View of anterior face of large tooth, enlarged ; 14 b, posterior face, showing well- 



defined median prominence in superior basal surface; 14 c, inferior basal surface; 

 14 d, profile section. Middle Devonian, TVaterloo, Iowa. 



( 



