PLATE XIV. 



Page. 

 PSAMMODUS TUMIDUS, St. J. and W 205 



Fig. 1 a. Maxillary tooth, right side, view from above, outline partially restored; 1 b, 

 do., posterior margin; 1 c, do., inner articular border; 1 d, do., from the 

 interior border. Upper Burlington; Bufflngton creek. Mr. St. John. 



Fig. 2 a. Similar views of a smaller example of the same form, left side, partially re- 

 stored outline. Same locality and collection. 



Fig. 3 a. A larger, irregular example of the same form, right side, seen from above, 

 outline restored, crown surface worn smooth; 3b, do., inner articular 

 border; 3 c, do., anterior margin. Same formation and locality. Mr. 

 Springer. 



Fig. i a. A broader tooth, referred to the mandible, right side, view from above, 

 showing rugose belt along the posterior margin; 4 b, do., from the pos- 

 terior margin; 4 c, do., inner articular border. Same formation, locality 

 and collection. 



PSAMMODUS GLYPTUS, St. J. and W 209 



Fig. 5 a. Mandibular tooth, right side, fragment seen from above, showing rugose 

 coronal surface; 5 b, do., from the anterior margin; 5 c, from the articu- 

 lar or inner margin. Upper Burlington limestone, main fish-bed; Cedar 

 creek, Illinois. Mr. Springer. 



Fig. 6 a. Maxillary tooth, right (?) side, from above, the dotted line may possibly 

 represent the proper restoration of the tooth; 6 b, do., posterior (?) mar- 

 gin; 6 c, do., profile section, showing the slight longitudinal convexity of 

 the coronal surface. Upper Burlington limestone; Quincy, Illinois. Prof. 

 Worthen. 



PSAMMODUS LOVIANUS, St. J. and W 207 



Fig. 7 a. Maxillary tooth, view from above; 7 b, do., from posterior margin: 7c, do., 

 anterior margin; 7 d, do., from the inner articular border; 7 e. do., ex- 

 terior border. Upper Burlington; Burlington, Iowa. Mr. Wachsmuth. 



Fig. 8 a. A small, narrow example of the same form, view from above, outline par- 

 tially restored; 8 b, do., from the posterior margin; 8 c, do., profile sec- 

 tion. Upper Burlington; Quincy, Illinois. Prof. Worthen. 



Fig. 9 a. Mandibular tooth, right side, view from above, partially restored in out- 

 line; 9 b, do., transverse profile from posterior margin; 9 c, anterior mar- 

 gin; 9 <l, do., articular border; 9 e, do., from the exterior border. Lower 

 Burlington; Burlington, Iowa. Mr. St. John 



