PLATE IV. 



PAGE. 

 Fig. 1-3. STENOPTEBODUS ELONGATUS, St. J. and W 106 



1 a. Maxillary posterior tootb, right raniuF, a medium size, somewhat worn spe- 



cimen, seen from above. Warsaw limestone; Warsaw 111. Coli, Prof. 

 Worthen 



2 a. A smaller tooth of the same form, left ramus, view from above, showing ob- 



lique direction of antero-lateral border, etc.; 2 ?>, do., inner margin; 2 c, 

 do.; profile from the posterior extremity. Same formation, locality and 

 collection. 



3 a. Mandibular posterior tooth, left ramus, an imperfect example, seen from 



above; 3 &, do., inner margin; 3 c, do., profile from anterior border. Same 

 formation, locality and collection. 



Fig. 4-8. STENOPTEBODUS PABVULUS, St. J. and W 107 



1 a. Maxillary posterior tooth, right ramus, from above. (The form originally 

 described under Scandalodus parvulus, N. and W.) St. Louis limestone; 

 St. Louis, Mo. . St. John. 



5 a. Maxillary posterior tooth, left ramus, view from above of a nearly perfect in- 



dividual. St. Louis limestone; St. Louis, Mo. O. St. John. 



6 a. Mandibular posterior tooth, right ramue, from above. Same formation; 



Alton, 111. Mr. Van Home. 



la. The same form, left ramus, view from above. St. Louis; Alton; Mr. Van 

 Home. 



8 a. Maiidibular median tootb, left ramus, seen from above; enlarged; 8 b. do., 



antero-lateral border; 80, do., inner margin: 8 d, do., outer inrolled mar- 

 gin. St. Louis limestone; St. Louis, Mo. Mr. Van Home. 



Fig. 9-14. STENOPTEBODUS PLANUS, St. J. and W 102: 



9 a. Maxillary posterior tooth, left ramus, from above;8 b, do., inner margin; 8 c, 



do., outer inrolled margin; 8 d, do., foreshortened view from the poste- 

 rior extremity. Upper Burlington fish-bed; Louisa county, Iowa. Coll. 

 Mr. Springer. 



10 a. The same form of right ramus, seen from above, outline restored. Same for- 



mation and locality. O, St. John. 



11 a. Mandibular posterior tooth, left ramus, seen from above; 11 b, do., inner 



margin; 11 o, do., outer inrolled margin; 11 d. do., foreshortened. View 

 from anterior border. Same formation and locality. Mr. Springer 



12 a. Same form of opposite ramus, from above. Same formation, locality and 



collection. 



13 a. Mandibular median tooth, left ramus, view from above, enlarged; 13 b, do., 



inner margin; 13 c, do., outer inrolled margin; 13 d, do., antero-lateral 

 border; 13 e, do., postero-lateral border. Upper Burlington; Augusta. 

 Iowa. 0. St. John. 



14 a. A large example of the same form, right ramus, view from above, borders 



restored; 14 b, do., inner margin; 14 c, do., outer inrolled margin; 14 d. 

 do., antero-lateral border; 14 e, do., postero-lateral border. Upper Bur- 

 lington; Louisa county, Iowa. Mr. Springer. 



Fig. 15-16. STENOPTEEODUS Sp? 105- 



15 a. Maxillary posterior tooth, left ramus, a worn specimen seen from above; 



15 b, do., inner margin; 15 e, do., outer inrolled margin. Keoktik lime- 

 stone; Warsaw, 1)1. Prof. Worthen. 



