EXPLANATION OF PLATE LIII. 



Page. 



FIG. 1 . Capului paralius 174 



la. Lateral view of type. (Mus. Michigan Univ.) 

 Ib . Lateral view of young specimen ( Keyes collection ) 

 Ic. Lateral view of another immature specimen. (Keyes collection.) 

 Id. Lateral view of a natural cast. (Collection of J. S. Newberry.) 

 Carboniferous, Kinderhook limestone. 



FIG . 2. Orthonychia formosum 189 



Lateral view of type, attached to the vault of Dorycrinus immaturus 



Wacns. & Spr. (Cjliection of Wachsmuth & Springer.) 

 Carboniferous, Kinderhook limestone. 

 FIG. 3. Orthonychia cornuformis. 

 FIG. 4. Strophostylus bivolvis (White & Whitfield) . 

 FIG. 5. Igoceras subplicatum . 

 FIG. 6. Capului lodensis. 

 FIG. 7. Capulus piso . + 



FIG 8. Capulus occidens . 



FIG. 9. Capulus haliotoides 174 



9a. Lateral view. (Collection of J. S. Newberry.) 

 9b. Apertural aspect of same. 



FIG. 10 . Igoceras quincyense. ..' 182 



lOa. Lateral view, apical portion broken. (Keyes collection.) 

 10D. Lateral view of an exfoliated specimen. (Keyes collection.) 

 lOc. Apical aspect of same. 



lOd. A specimen attached to the vault of Physetocrinus ventricosus Hall, lower 

 portion of the crinoidal calyx not shown. (Collection Wachsmuth & 

 Springer.) 

 Carboniferous, Burlington limestone. 



FIG. 11. Capulus tribal osus 175 



lla. Lateral view. (Keyes collection.) 

 lib. Dorsal aspect of same. 



lie. Lateral view of type. (Collection of E. O. Ulrich .) 

 Carboniferous, Burlington limestone. 



FIG. 12 Capulus biserialis 177 



12a. Lateral view of type. (After Meek & Worthen.) 

 12 b. Dorsal aspect of same. 



Carboniferous, Burlington limestone. . 



FIG. 13. Capulus latus 17& 



13a Dorsal view of type. (Keyes collection.) 

 13b. Lateral aspect of same. 



Carboniferous, Bailington limestone . 



FIG 14. Capulus obliquus 177 



14a. Dorsal view of type. (Keyes collection.) 

 14b. Lateral aspect of same. 



Carboniferous, Burlington limestone . 



FIG 15. Orthonychia cyrtolites .188 



Lateral aspect. (Keyes collection.) 

 Carboniferous, Burlington limestone . 



