EXPLANATION OF PLATE LXXVII. 



Figs. 1-20. ATHYRIS CRASSICARDINALIS White p. 471 



1-2. Exterior and interior views of a brachial valve. 3-4. Exterior 

 and interior views of a small pedicle valve. Cotypes. (U. M., 

 No. 1358.) 



Kinderhook, Bed No. 7, Burlington, Iowa. 



5-6. Exterior and interior views of a brachial valve. 7. Posterior 

 view of a shell with both valves in articulation. 8-9. Exterior 

 and interior views of a small pedicle valve. 10-11, and 

 12-13. Exterior and interior views of two pedicle valves. 

 14-16. Exterior views of three pedicle valves. 17-18. Exterior 

 and interior views of a brachial valve. 19. Exterior view of 

 a brachial valve. 20. Interior view of a brachial valve. (W. 

 M., No. 9817.) 



Chouteau limestone, Sedalia, Missouri. 



Figs. 21-25. ATHYRIS CRASSICARDINALIS White (??). 



21-23. Pedicle, brachial and lateral views of a nearly complete 

 pedicle valve. 24-25. Views of two brachial valves. (W. M., 

 No. 6679.) 



Kinderhook, Bed No. 6, Burlington, Iowa. 



Figs. 26-31. AMBOCOZLIA LEVICULA Rowley p. 426 



26-28. Pedicle, brachial and lateral views of a metatype. 29-31. 

 Similar views of the same specimen enlarged (x4). (R. R. R.) 

 Burlington white chert, Louisiana, Missouri. 



Figs. 32-35. AMBOCCELIA PARVA Weller p. 424 



32-33. Views of two pedicle valves, cotypes. 34-35. Views of the 

 same specimens enlarged (x4). (W. M., No. 5952.) 

 Northview sandstone, Northview, Missouri. 



Figs. 36-43. AMBOCCELIA UNIONENSIS n. sp p. 425 



36-37. Views of two pedicle valves. 38-39. Views of the same 

 specimens enlarged (x4). 40. View of a brachial valve. 

 41. View of the same specimen enlarged (x4). 42-43. Views 

 of two large pedicle valves. Cotypes. (W. M., No. 14782.) 

 Kinderhook, Z l / 2 miles northwest of Jonesboro, Illinois. 



Figs. 44-54. AMBOCCELIA MINUTA White p. 423 



44-47. Pedicle, brachial, lateral and posterior views of a large 



specimen (x4). 48-50. Pedicle, brachial and lateral views of 



another specimen (x4). 51-54. Pedicle, brachial, lateral and 



posterior views of a third specimen (x4). (W. M., No. 6719.) 



Louisiana limestone, Louisiana, Missouri. 



Figs. 55-59. COMPOSITA (?) CORPULENTA (Winchell) p. 495 



Pedicle, brachial, lateral, anterior and posterior views of a nearly 

 complete specimen. (W. M., No. 13899.) 



Chonopectus sandstone, Burlington, Iowa. 



171 



