Plate 12. 



Fig, 1. Ldtuotuha lituiformis. X 20. H80, U.S.N. M. No. 10467. 



2. Lituotuba lituiformis. X 15. H405, U.S.N.M. No. 10472a. 



3. Ammobaculites agglutinans. X 20. D2043, U.S.N.M. No. 10499. 



4. Ammobaculites pseudospirale. X 35. (After Williamson.) 



5. Ammx>baculites cassis. X 35. (After Brady.) 



6^and 7. Ammobaculites americanus. X 20. (After Brady.) 



101 



