Plate 4 



Figures 1-4. Nonion grateloupi (d'Orbigny). Specimens from Tortugas, Fla., 

 sho\Aing variation in shape in side view. X 100. 

 5. Nonion barleeanum (Williamson). (After Williamson.) 

 6-12. Nonion labradoricum (Dawson). Fig. 6. (After Morton.) Fig. 7. 

 (After Dawson.) Fig. 8, Gaspe Bay. X 60. Figs. 9, 10, Casco 

 Bay, Me. X 60. Figs. 11, 12, Albatross D 2202, Northeastern 

 coast of United States. X 60. 



61 



