EXPLANATION OF PI.ATP: X. 



LUCINA TUISILCATA Coiliad (]>. M). 



Kills. 1,2. Oppositi! views of .a left valve, eularged; the oiiMiiie .sliows the natural size. 

 ;t, 4. Similar views of a right valve enlarged. 



LiciNA Acn.iNis Coiirail (p. fili). 



Fios. fi.ti. Copies of Mr. Conrad's figures, Miocene Foss., I'l. x\i. fig. 2. none of the New .Jersey 

 exani]ile8 being ))erfect enough to figure. 



Ltxina ciiExri.ATA Conrad (p. (iS). , 



Fkjs. 7, H. !). View of shells with the unibonal sulcus near the cardinal margin. Enlargeil. 

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

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

 14, ir>. Cardinal views of the valves iu conjunction. 

 All lignres enlarged three diameters. 



Cardh'M (Ckrastoderma) chatuti.oidks Conrail (p. (!t'i.) 



Fios. lt>, 17. Opposite views of the most perfect v.alve obtained. 



IH. View of a fr.igmeiit 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. 

 .x.xxvii, fig. 7. 



