Plate 7 



Figures 1. Elphidiuni alvarezianum (d'Orlngny). (After d'Orbigny's type fig- 

 ure.) a, side view; h, apertural view. 

 2, 3. Elphidium alvarezianum (d'Orbigny). X 60. From pliotographs of 

 specimens from off Fallcland Islands. 



4. Elphidium incertum (Williamson). (After Williamson.) a, side 



view; b, apertural view. 



5. Elphidiuvi incertum (Williamson). X 60. (After H. B. Brady.) 



From Challenger Station 46, North Atlantic. 



6. Elphidium incertum (Williamson). X 50. (After Heron-Allen 



and Earland.) From off west coast of Scotland. 



7. Elphidium incertum (Williamson). X 50. (After Heron- Allen 



and Earland.) From off west coast of Scotland. 



8. Elphidium incertum (Williamson). X 80. From off Bates Island, 



Casco Bay, Me. a, side view; h, apertural view. 



9. Elphidium incertum (Williamson). X 80. From Hudson Bay. a, 



side view; h, apertural view. 

 10. Elphidium incertum (W^illiamson), var. clavatum Cushman, new 

 variety. X 60. From Spar Landing, Frenchmans Bay, Me. 

 a, side view; h, apertural view. 

 64 



