TAB. VIII. 



Pachyrisma grande, anterior view, p. 79. 



„ posterior view, showing ligamental area, p. 79. 



hinge area of right valve, p. 79. 

 „ hinge area of left valve, p. 79. 



„ side view, p. 79. 



Unicardium parvuhmi, p. 74. 

 ,, varicosmn, /;. 73. 



„ „ nucleus of ditto, jo. 73. 



„ impressum, p. 73. 



