EXPLANATION OF PLATE X. 



Lucina trisulcata Conrad (p. 64). 



Figs. 1, 2. Opposite views of a left valve, enlarged ; the outline shows the natural size. 

 3, 4. Similar views of a right valve enlarged. 



Lucina acclinis Conrad (p. 62). 



Figs. 5,6. Copies of Mr. Conrad's figures, Miocene Foss., PI. xvi, fig. 2, none of the New Jersey 

 examples being perfect enough to figure. 



Lucina crenuuata Conrad (p. 63). 



Figs. 7, 8, 9. View of shells with the umbonal sulcus near the cardinal margin. Enlarged. 

 10, 11. Views of a valve with a wider border. 

 12, 13. View of a shell with a longer anterior end. 

 14, 15. Cardinal views of the valves in conjunction. 

 All figures enlarged three diameters. 



Cardium (Cerastoderma) craticulqides Conrad (p. 6^.) 



Figs. 16, 17. Opposite views of the most perfect valve obtained. 



18. View of a fragment of a larger valve, showing the character of the narrow ribs. 



19. Copy of Mr. Conrad's figure, showing the entire form of a valve; Miocene Foss., PI. 



xxxvn, fig. 7. 



164 



