PLATE XXVI. 



PAGE 



Fig. 22. Fu8US tumidus. Magnified. 145 



Fig. 23. F. occidextalis. Magnified. 146 



Fig. 24. Neptuxea (Tritoxofusus) cketacea. 146 



Fig. 25. N. mucroxata. Natural size. 147 



Fig. 26. Pal.£ATRACTUS crassus. Magnified. 148 



Fig. 27. Surcula PR41ATTENUATA. Natural size. 150 



Fig. 28. S. (Surculites) sixuata. Natural size. 150 



Fig. 29. S. (Surculites) ixcoxspicua. Magnified. 151 



Fig. 30. HeterOterma trochoidea. Magnified. 152 



30 a. Top view, showing the posterior sinus. 



Fig. 31. Bela clathrata. Magnified. 152 



Fig. 32. Cordiera mitrjeformis. Magnified. 153 



Fig. 33. Tritoxium Califorxicum. Magnified. 154 



Fig. 34. Trachytritox Tejoxexsis. Natural size. 154 



Fig. 35. Brachysphixgus sixuatus. Natural size. 156 



Fig. 36. Bullia (Molopophorus) striata. Magnified. 157 



Fig. 37. Turbixella crassitesta. Natural size. 157 



