PLATE V. 



PAGE. 



STig. 1. D^LTOPTTCHius WACHSMUTHI, St. 3. and W 98 



1 a. Posterior tooth of the left rainus of the mandible, viewed from above, bro- 

 ken extremity restored in outline; 1 b do., seen from the antero-lateral 

 border: 1 c do., showing inner margin. Keokuk limestone, Warsaw, 111. 

 Coll. Prof. Worthen. 



Fig. 2 a. A similar and more perfect tooth of the right rarnus of the mandible, seen 

 from above; 2 b do., autero- lateral border; 2 c do., postero-lateral border, 

 Same formation, locality and collection. 



Fig. 3 a. Posterior tooth of the left rarnus of the upper jaw, from above; 3 b, do., pro- 

 file from the inner margin. Same formation, locality and collection. 



Fig. 4 a. Maxillary posterior tooth, right ramus, view from above; 4 b do., outer in- 

 rolled margin. Same formation, locality and collection. 



Fig. 5 a. Maxillary posterior tooth and median series of teeth; 5 b do., right ramus, 

 seen from above, outline restored. Keokuk limestone, Danville, Iowa. 

 Coll. Mr. Wachsmuth. 



DELTOPTTCHIUS PKIMUS, St. J. and W 93 



Fig. 6 a. Mandibular posterior tooth, left ramus, seen from above, outline restored. 



Upper Burlington fish-bed; Louisa Co., Iowa. Mr. Springer. 

 Fig, 7 a. Maxillary posterior tooth, right ramus, viewed from above, outline restored. 



Same horizon and locality. O. St. John. 

 Fig. 8 a. Maxillary posterior tooth, left ramus, from above. Same formation and 



locality. Mr. Springer. 



DELTOPTTCHIUS EXPANSUS, St. J. and W 98 



Fig. 9 a. An imperfect posterior tooth of left ramus of mandible, showing coronal 

 contour, seen from above, outline restored. St. Louis limestone; Alton, 

 111. Coll. Mr. Van Home. 



Fig. 10 Q. Mandibular posterior tooth, right ramus, seen from above. St. Louis lime- 

 stone; St. Louis, Mo. Coll. Prof. Worthen. 



Fig. 11 a. A large mandibular posterior tooth, from above, the coronal contour ob- 

 scured by wear. St. Louis limestone; Waterloo, 111. Coll. Prof. 

 Worthen. 



Fig. 12 a. Maxillary posterior tooth, right ramus, from above, outlinelrestored. St. 

 Louis limestone; Alton, 111. Coll. Mr. Van Home. 



Fig. 13 a. Similar tooth, left ramus of upper jaw, view from above. Same format'on, 

 locality and collection. 



DELTOPTTCHIUS VABSOVIENSIS, St. J. andW 96 



Fig. 14 a. Mandibular posterior tooth, left ramus, view from above, alate posterior 

 border restored in outline; 14 b do., enlarged; 14 c do., showing antero- 

 lateral border, enlarged; 14 d do., seen from the outer inrolled margin. 

 Warsaw formation; above Alton, 111. Mr. Van Home. 



Fig. 15 o. Maxillary posterior tooth, right ramus, seen from above. Warsaw forma- 

 tion; Warsaw, 111. 



DELTOPTTCHIUS NITIDUS, Leidy sp 99 



Fig. 16 o. Mandibular posterior tootb, left ramus, seen from above, outline restored; 

 16 b do., antero-lateral border; 16 c do., foreshortened view from pos- 

 tero-lateral border; 16 d do., outer inrolled extremity; 16 e do., inner 

 margin. Chester limestone; Chester, 111. Coll. Prof. Worthen. 



